WiFi going into sleep mode?

Hi,

Yesterday I had to change the location of my Heltec device, so that I could put antenna out of the window (otherwise there was no LoRa communication). To do so, I had to connect the device to a WiFi.
Today I woke up and found that the devices blockchain is desynced (see the image).

This has not happened before on cable connection.
I was able to enter the administration panel through WiFi with no problem, although it was loading pretty slow, so the device did not disconnect/forget the network.

Is it possible that WiFi goes into sleep mode when there is “no action”?
Are there any logs for the WiFi connection?

Kind regards
Mateusz