@droftarts Is there anything else I should try?

@droftarts The duet has its antenna as part of the board. The router is probably 15 feet away, but on the floor above (so diagonally from the printer).

I tried switching it to both channel 6 and channel 11, but I am still getting the "Authentication failed" error.

My cordless phone is pretty close, so I tried unplugging it, but still nothing.
I also tried adjusting the antennae on my router; it improved my RSSI from -56 dBm to -51 dBm. That didn't seem to help either. But maybe that is still not strong enough?

@droftarts

Thanks for all your continued help! I really appreciate it. Yep, it is set to the standard WPA2-PSK; I triple-checked it. Could encryption type have anything to do with it? I see options for either TKIP or AES. I don't really know what they mean, but at this point I'm just trying anything that might work haha.

@Phaedrux
That's what it seemed like to me too; that's why I created a special guest network that only runs on 2.4 GHz and has a simple password that is impossible to mess up

@droftarts

Thanks so much for this! I'm definitely getting fewer error messages now. It still won't connect to my wifi though; I am now getting this message:

READ: Error: WiFi module reported: Authentication failed

@Phaedrux It worked! I was able to control the printer using DWC. Does that indicate that the issue could be my wifi? Is there anything else you know of that I could check?

@droftarts

Hi! Yep, here it is (I have my actual SSID and password in place of "SSID" and "password"):
M552 S-1 ; turn off wifi
G4 S2 ; wait for wifi state to change
M552 S0 ; turn on wifi in idle mode
G4 S2 ; wait for wifi state to change
M588 S"*" ; if necessary, delete all existing saved SSIDs
G4 S2 ; wait for wifi state to change
M587 S"SSID" P"password" ; add new SSID
G4 S2 ; wait for wifi state to change
M552 S1 ; enable networking

I ran M587 again and it is saying
READ: LAB IP=0.0.0.0 GW=0.0.0.0 NM=0.0.0.0

Also it is now saying this:
READ: Error: WiFi module reported: Didn't find access point while trying to connect to LAB

I created the SSID called LAB specifically to only run on 2.4 GHz, so I'm sure it's not trying to connect to 5 GHz

@droftarts

Thanks for this! Yep, Simplify3D has it! I use it with an identical printer at work and it seems to do great. Just in case though, I created the runonce.g file as you said and put it in the /sys folder. Unfortunately, I am still getting the following:
READ: Error: WiFi module reported: no known networks found
READ: WiFi module is idle

@Phaedrux

Thanks for your reply!
I'm using Simplify3D over USB.

Here are the responses to the following commands (I changed mentions of my SSID to "SSID"):
M552:
READ: WiFi module is idle
M552 S-1:
READ: WiFi module stopped
M552 S0:
Usually says: READ: WiFi module is idle
Right after M552 S-1 it says: READ: WiFi module started
M552 S1
READ: Error: WiFi module reported: Failed while trying to connect to SSID
M587
READ: Remembered networks:
READ: SSID IP=0.0.0.0 GW=0.0.0.0 NM=0.0.0.0
READ: ok
READ: Error: WiFi module reported: Failed while trying to connect to SSID
READ: WiFi module is idle

And here is the response to M122:

READ: === Diagnostics ===
READ: RepRapFirmware for Duet 2 WiFi/Ethernet version 3.4.6 (2023-07-21 14:08:28) running on Duet WiFi 1.02 or later + DueX5v0.11
READ: Board ID: 0JD2M-9F8TA-GJ4TJ-6JTD0-3SN6T-K6SL4
READ: Used output buffers: 1 of 26 (3 max)
READ: === RTOS ===
READ: Static ram: 23896
READ: Dynamic ram: 78004 of which 0 recycled
READ: Never used RAM 10180, free system stack 193 words
READ: Tasks: NETWORK(ready,7.7%,325) HEAT(notifyWait,0.0%,333) Move(notifyWait,0.0%,363) DUEX(notifyWait,0.0%,24) MAIN(running,92.1%,461) IDLE(ready,0.2%,30), total 100.0%
READ: Owned mutexes: USB(MAIN)
READ: === Platform ===
READ: Last reset 00:07:50 ago, cause: power up
READ: Last software reset details not available
READ: Error status: 0x00
READ: Aux0 errors 0,0,0
READ: Step timer max interval 0
READ: MCU temperature: min 13.6, current 21.6, max 21.8
READ: Supply voltage: min 0.0, current 0.6, max 0.9, under voltage events: 0, over voltage events: 0, power good: no
READ: Heap OK, handles allocated/used 0/0, heap memory allocated/used/recyclable 0/0/0, gc cycles 0
READ: Events: 0 queued, 0 completed
READ: Driver 0: ok, SG min n/a
READ: Driver 1: ok, SG min n/a
READ: Driver 2: ok, SG min n/a
READ: Driver 3: ok, SG min n/a
READ: Driver 4: ok, SG min n/a
READ: Driver 5: ok, SG min n/a
READ: Driver 6: ok, SG min n/a
READ: Driver 7: ok, SG min n/a
READ: Driver 8: ok, SG min n/a
READ: Driver 9: ok, SG min n/a
READ: Driver 10:
READ: Driver 11:
READ: Date/time: 1970-01-01 00:00:00
READ: Cache data hit count 4294967295
READ: Slowest loop: 99.78ms; fastest: 0.13ms
READ: I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0
READ: === Storage ===
READ: Free file entries: 10
READ: SD card 0 detected, interface speed: 20.0MBytes/sec
READ: SD card longest read time 3.1ms, write time 0.0ms, max retries 0
READ: === Move ===
READ: DMs created 83, segments created 0, maxWait 0ms, bed compensation in use: none, comp offset 0.000
READ: === MainDDARing ===
READ: Scheduled moves 0, completed 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
READ: === AuxDDARing ===
READ: Scheduled moves 0, completed 0, hiccups 0, stepErrors 0, LaErrors 0, Underruns [0, 0, 0], CDDA state -1
READ: === Heat ===
READ: Bed heaters 0 -1 -1 -1, chamber heaters -1 -1 -1 -1, ordering errs 0
READ: === GCodes ===
READ: Segments left: 0
READ: Movement lock held by null
READ: HTTP is idle in state(s) 0
READ: Telnet is idle in state(s) 0
READ: File is idle in state(s) 0
READ: USB is ready with "m122" in state(s) 0
READ: Aux is idle in state(s) 0
READ: Trigger is idle in state(s) 0
READ: Queue is idle in state(s) 0
READ: LCD is idle in state(s) 0
READ: Daemon is idle in state(s) 0
READ: Autopause is idle in state(s) 0
READ: Code queue is empty
READ: === DueX ===
READ: Read count 1, 0.13 reads/min
READ: === Network ===
READ: Slowest loop: 1.35ms; fastest: 0.00ms
READ: Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0)
READ: HTTP sessions: 0 of 8
READ: = WiFi =
READ: Interface state: changingMode
READ: Module is trying to connect
READ: Failed messages: pending 0, notready 0, noresp 0
READ: WiFi firmware version 1.27
READ: WiFi MAC address 4c:75:25:1c:0d:5e
READ: WiFi Vcc 3.37, reset reason Power up
READ: WiFi flash size 2097152, free heap 29240
READ: Clock register 00002002
READ: Socket states: 0 0 0 0 0 0 0 0

I am setting up my duet for the first time (haven't even powered on the printer yet) and it will not connect to my wifi; it gives this error:

READ: Error: WiFi module reported: Failed while trying to connect to SSID

I have tried the following:
Adjusting my router antennas to make the signal stronger (currently the RSSI = ~50)
Setting a special guest network on my wifi to ensure that the printer is only trying to connect to a 2.4 GHz network
Setting the SSID and password to different values of varying simplicity (so I know that I am definitely typing them in correctly)
Erasing the remembered network via the M588 command then resetting it with M587
Typing in M122; when I did that the response to "Reset reason" said "Power up". Duet's troubleshooting page suggested I post to this forum if it said anything besides "Turned on by main processor", so here I am

Also, the wifi module on the actual circuit board doesn't ever blink blue; it only blinks a greenish yellow. But I'm not sure if this version just uses this color instead of blue?

Any help would be greatly appreciated!