Faced such a problem, using NodeM from RoboDyn.
On other firmware Wifi works fine. But Espruno does not find an access point. All of the above does not help either.
If you bring the board close to the router, it finds access points. This means a problem in a weak signal. Tried NodeMCU firmware. An excellent signal, the problem is still in the firmware, but not in the hardware. Different signal strength settings?