WiFi.softAPdisconnect(false);
WiFi.enableAP(false);
I first found this in the documentation:
https://arduino-esp8266.readthedocs.io/ ... disconnect
softapdisconnect(wifioff);
Function will set currently configured SSID and password of the soft-AP to null values. The parameter wifioff is optional. If set to true it will switch the soft-AP mode off.
Using that caused my board to continually crash. Not sure where the rest of the docs are for the 2 calls you are making.. they are not even listed there.
The part of this that caused me to really need to shut it off is that I am using Sonoff basics for a project and they were all coming up with the same softAP default ssid("ESPsoftAP_01" and IP("192.168.4.1").
Made it for some weird debugging. This is what was affecting my IO since I was reporting back to a control system that would get results from multiple devices identifying as the same device.
I did experiment with seeing if it came back after removing these lines and it does.
I hope my additional comments here help someone find this faster than I did.