ESP32 - Solving the problem of WiFiManager "failed to connect"

This post is a quick summary on how to solve the always "failed to connect" issue when using WiFiManager on ESP32.

The Symptom

The password is saved but the Connection Result always returns 1 (Failed to connect).

*WM: WiFi save
*WM: Sent wifi save page
*WM: Connecting to new AP
*WM: Connecting as wifi client...
*WM: Connection result:
*WM: 1
*WM: Failed to connect.

If you reset manually the board the connection will established, so the password is correctly stored.
I tried with old Arduino core version and all functionality work correctly, so should be a problem whit some modification on new commit (is there also some IDF sdk update)