When I do a connection attempt over VPN does the Wifi-Module restart without configuration and open at channel 1 a open access point.

I think there is a bug in the firmware.

I can also not connect my Duet Wifi over my private (L2TP) VPN. After a connection attempt over VPN lose Duet Wifi the Wifi connection.
So I must reset the board.

Hello,

after power on reset, all my default temperature settings for heater and bed get be lost. What can I do?

I have

Firmware Name: RepRapFirmware for Duet WiFi
Firmware Electronics: Duet WiFi 1.0
Firmware Version: 1.18beta3 (2017-03-16)
WiFi Server Version: 1.03 (ch fork)
Web Interface Version: 1.15-b2