Hass.io on rpi3 stops delivering on port 8123

I installed hass.io on an rpi 3B+ to replace my old venv setup on an rpi2. Quite nice otherwise, but the iOS apps and web page on port 8123 stop responding after a while (sometimes minutes, sometimes half an hour). At first I thought the rpi was crashing, but then noticed that it keeps filling the history logs with events all that time (for example from my Ikea Trådfri hub).

I tried keeping a CLI window open, and that particular web page seems to stay responsive indefinitely. So apparently open network connections keep on working, but new connections are refused. Any ideas what might be going on?

The setup is on wifi, internal network address using IP number (not DNS), IP fixed via MAC at the router.

The documentation indicates that you should only install Home Assistant OS (that’s the new name for hassio for the last 6 months) on an RPi2 for testing purposes, not for use as a production server.

Performance expectations

This is a list of popular platforms and what to expect from them.

Platform Notes
Raspberry Pi Zero/Pi 2 Only use these for testing

OK, maybe this got up on the wrong foot… let me rewrite that sentence:
“I installed Home Assistant OS on rpi 3B+”.

The problem remains, though.

OK, yesterday I connected to wired Ethernet and the connection has worked ever since. Slightly annoying, since the old rpi2 setup with an external WIFI dongle was rock solid and my interior decor won’t like the wired setup.

Anyway, off to create & solve other problems. Next I’ll reinstall to SSD…