[UrushibaraRuka]

So the server is pretty much across the street for me (I'm from Frankfurt).

https://db-ip.com/138.68.75.163

Postal code 60313, apparently

Again, it only happend once per boot. Also not that much of a big deal, just a tiny bit annoying.

Then again, it might be my router as it's in service for about 5 years or so. Maybe it wants to retire

Can you post your kernel log using dmesg | pastebinit (or click the crash log option in LibreELEC Settings) and then post the link.. 

 Sorry for the late reply.
According to the Zip-Code the server is about 1.5km away. I'll reset my connection later on (it's up for about 6 months now without a break) to see if it's a peering issue, but seeing that my desktop can load with full speed I suspect an issue with my router port.

As for the other issue I mentioned, I tried to trigger it over the past few days but it seems to be gone since the clean install.
And I really tried hard to trigger it again. If it happens again I'll post a debug log but I fear it won't happen again anytime soon.

Anyway, thank you for all your hard work and your support!