^^^ This is the exact same problem I have been having. No matter how I change the config.g, The access point will not start automatically after Boot up. I have to manually enter M552 S2 through the console to turn it on. Once on, though, it has been flawless.

I upgraded to 1.21RC2 and tried clearing the flash but I am still struggling with the same problem. A simple send from the terminal activates the access point, but it will still not connect on startup.

How and where in the config.g do you have your M552 S2 command?

I have tried the M552 S2 command in config.g by:
1. changing line 3 in config.g from M552 S1 to M552 S2
2. changing line 3 in config.g from M552 S1 to M552 S0, then adding M552 S2 immediately after or at the very end
3. using G4 S120 at the end of the code followed by M552 S2

Each of these results in the same issue:
After powering down, On startup the duet broadcasts an open wifi access point named "AI-THINKER_2FBDDD"
To get my custom access point to initiate, I have to wait about 30-60 seconds after power on, then open a terminal and send M552 S2

Any suggestions?

I updated the firmware, wifi server and web interface to version 1.20. I was able to successfully initiate and utilize the access point mode, nearly flawlessly. When I cut power to the printer and turned it on again, the Duet forgot the settings.

Is there a way to write these settings to EEPROM, or should they already be saved by using the M589 command?