SMB transfer unreliable - frequent drop of the connection to my NAS during Time Machine backup

Hi,

no, I did not notice disconnect on other devices. Interference is not very likely (see attached spectrum measurement). Very rarely a second user is also on channel 36, but at a very low level.

I noticed that it usually needs a transfer of a few 100GBytes for the disconnect to occur. What is especially strange, is that the connection recovers very fast after that. I only could find it through log messages - in this case I tried copying to a disk image using Superduper, which clearly indicated that disconnect on the target side in its log after failure. Time machine only indicated a transfer error not telling on which side it happened.

I am not using 2.4GHz at all on the XR500 as it is simply too slow and as you can see far too congested in my area (Picture of spectrum in my area).

Greetings

Andreas