I have been operating this repeater for several months with a cable connection to the router (FritzBox) - however not in the operating mode "repeater" but as a pure "AccessPoint" (I have deactivated the WLAN on the router/FritzBox).
In this set-up, the repeater works perfectly - but there are no handovers...

Unfortunately, I am not yet in possession of the repeater, as I live further abroad. I will start using the repeater at the beginning of September. I already use the smaller Repeater 310 in our house and am completely satisfied with it. The only thing I miss is the 5GHz range. I have never connected the repeater via cable. Unfortunately, I can't say anything about that.
I use the 310 outside for guests and the 1750E inside for my own use.