No need to apologize, i am happy to have this build and this awesome thread!
i am embarrassed and i feel stupid but somehow the issue disappeared. Not sure if the issue has been caused by the vdsl modem in front of the router or if i did misconfigured something essential... I am unable to do more testing without my wife killing me....
The router keeps running now without issues. Syslog looks fine..
Sorry guys about the panic.
//EDIT:
I have found the issue after it reoccured:
The image is working fine but my upload was fully occupied and caused bufferbloat. High latency and slow downloads. Terrible connection. The upload was running at max speed in the meantime.
I simply could solve the issue the following way:
- enable Smart Queue Management (Network - SQM QOS)
- Change the interface to WAN
- Select the right speed settings and change the link layer adaption to VDSL2
Sorry again! Issue found on my side!!