BK7231N CBU Module Smart Circuit Breaker Not Connecting to WiFi After OpenBK Flash

I received another smart circuit breaker, this time with a CBU module (rather than the BL602-based PTBLU-W module that was in my two other circuit breakers.
https://www.aliexpress.com/item/1005007234329066.html (SY2 version with power monitoring)

Now I have a weird problem: I've successfully flashed OpenBK 1.18.135 (and also 1.18.124 for comparison purposes). There is no problem at all accessing the device when it is in AP mode. But no matter what I try, I can't get it to connect to my main wifi (that every other gadget is connected to, including the BL602 devices). It will, however, connect to my cell phone when I turn on hotspot.

For comparison, the device connected perfectly to my main wifi when it was still running the original Tuya firmware, so I don't think it is a hardware issue.

Are there known issues with connecting BK7231N devices to wifi? Or particular settings that must/or must not be used in the wifi setup?

I'll post a tear down once I have the wifi working and can get the correct config.

Thanks for any help and suggestions.

Does you wifi has WPA3 enabled? I think bk7231 devices does not work with that.