WiFi stays "connected" when access point is out of range

It happens from time to time that the WiFi (according to the indicator in the top status bar) stays connected, even when I'm far out of range of the access points of that specific WiFi network. The network is than still "available" but does not work.

If I ping for example, I get the Destination Host Unreachable message.

If I disable the WiFi from the quick settings, the network starts working again (via 4G).

See the log for details:

WiFi-connected-while-out-of-reach.log

I left the house after roughly 15:35

Then you see in the log messages like this:

Apr 14 15:38:53 avalon kernel: redpine_91x: Antenna is changed to 3
Apr 14 15:39:19 avalon kernel: redpine_91x: Antenna is changed to 2

They keep appearing until I brought the interface down and up again:

Apr 14 16:08:18 avalon kernel: redpine_91x: <==== Interface DOWN ====>
Apr 14 16:10:16 avalon kernel: redpine_91x: <==== Interface UP ====>

At 16:10 I enabled WiFi hotspot, the issue happened before that.

Maybe related to issue #308.