@qurt I think the name has changed since DWC 3.4.x. I think 'Time to wait between AJAX retries (ms)' (3.5.3) is the same as 'Extended status update interval' (3.4.x).
Set 'Extended status update interval' and 'Update interval (ms)' to 250ms. 20ms is definitely too short. The default should be 200ms, so it seems that a zero may have been deleted, and might be the cause of your issues.
The defaults in 3.5.3 are:
f79608aa-32ec-47cd-a3c2-18cab122575d-image.png
If you want do return to the defaults, delete sys/dwc-settings.json (you can do this in DWC) and reload the page in your browser. A new dwc-setting.json will be created as soon as you change anything.
Ian