Wifi is generally kinda hard to troubleshoot, but you could try to set the "log_level" to 0 to maybe have some better hints in the logs. I could also tell you to look at your transmit power, but I assume you've already done that and that's not something that should change with time anyway.
It's already in the kernel in most linux distributions since a few years at least. And it is pretty cool.
Wifi is generally kinda hard to troubleshoot, but you could try to set the "log_level" to 0 to maybe have some better hints in the logs. I could also tell you to look at your transmit power, but I assume you've already done that and that's not something that should change with time anyway.