Strange behavior of Odroid N2+ with HA after restart of a Network Switch

I had something strange today… did an upgrade of all my Ubiquity devices (except my UDM Pro where HA is connected to…)

But for some reason, when all the upgrades where done, HA did not respond anymore… only acted on a ping, but no connection was possible anymore.

After that, I rebooted my UDM Pro, but still nothing… is was (again) responding to a ping.

After a reset of the Odroid (power off… 2/3 seconds wait, power on…) then ping was even not possible anymore… as a last resort I cut the power and waited 1 minute before powering it on again and it worked again!

Maybe the firmware updates in my network triggered something HA did not like … because it was in the same time frame… but the scary thing is that after the reset (2/3 seconds power off/power on is for me a reset) it did not came up anymore…

Someone with same experiences?

What should I do next time? Are there things which I should check (for example in my network…?)