Wifi connections disappear an hour after startup

Wifi works for the first hour after starting up. Here’s what nmcli gives me initially:

However, my laptop later can’t find any Wifi connections (at all), and I have to reboot if I want Wifi back. Here’s what nmcli gives me then: (picture in first comment)

Interestingly, GENERAL.HWADDR changes, but I’m not sure if that’s the cause or a symptom.

This is what nmcli gives me after all the Wifi connections vanish:

What does the output of ip address show display for that interface when it is connected?
Of interest would be this line valid_lft 76544sec preferred_lft 76544sec

To me it sounds like the AP is limiting the connection time (1 hour is 3600sec) and causing the disconnect when the lease times out, but dhclient fails to renew the dhcp lease.

I think the GENERAL.HWADDR may be a random generated MAC when the connection is made, and that when the lease renews it is retained, but is generated new when a new connection is made.

Just of interest.
Where is this happening? At home?, at work?, or at some free AP location such as a coffee shop or library?
Some locations may prevent long term connections deliberately and thus block dhcp lease renewal.

Dear Jeff,

Thanks for your reply! The trouble is that it’s not always an hour (sometimes it’s ten minutes), and it’s not just one network that disappears, but every single wifi connection.

By the way, when the wifi breaks, nmcli eventually gives me status 20 (unavailable), instead of the 30 (disconnected) as in the screenshot above.