AR750S-ext diagnostics


I have a new AR750S-ext three days connected to my lan. I flashed 4.103 without and 4.103 with adguardhome on it. Both firmwares are not consistently and often slow or had strange behaviour.
My conclusion is there must be a hardware failure which is the cause of this strange behaviour.
Is there a possiblity to check the device if it is working like it should?

I have installed several routers in a lan but this is getting ridiculous.

Please advice.

Grtzz tom

AGH functionality is being tested. Have you done anything special in AGH, such as adding large filter lists?