LilyGo ESP32 T-CAN485 devboard wifi disconnections

Good morning
i have 2 of these board both have been programmed with the code from here

now they both have the same code and same settings(this was to trouble shoot)
to confim
but one of them falls off the wifi where the other one does not and looks liek it stops responding to web interface or ping
Sorry i am new to this
how can i tell if it is the board at fault , the wifi has just dropped or some thing else is wrong with this one
is there any debugging via usb or similar i can do or find out why the device is either no responding
thanks
martin

Start by posting your code and an annotated schematic. Be sure to show all power sources, grounds and note any lead over 10"/25cm.