Further to @Sparkie’s post there are several threads on this on the BraX3 Forum. As mentioned it’s a known bug with connecting to a small number of specific routers (and/or WPA2) and is being worked on now by LineageOS. Hopefully there will be an update to resolve it passed to iodéOS soon for the BraX3 (its a combined OS and hardware issue). However it may also just be a settings issue or similar for you.
In the meantime you may want to look through these and check if you have the same situation, or the same model router as others have reported, or similar, in which case it may or may not be fixable right now. But you can try some of the suggested actions to see if it resolves it too, that will be in some of these threads…
The official BraX3 one:
Also these - unfortunately many of them do duplicate some info, but hopefully you will find things to check or try and/or identify for sure if your router is one of the ones affected, that the phone and it won’t play nicely together…