I have a SH2 with 3 x black wi-fi discs. One of them is already extended using cat6, works fine. However it only works on a straight cable, if I put a small gig-capable unmanaged switch in-line then the disc dies (flashing red) frequently. I assume there's something in the mesh protocol that isn't quite standard? I haven't gotten as far as packet capture to see what's going on.
Note: this was prior to the most recent firmware update on 16th October 2020, have not retested since.
However thought I'd check if anyone's got a gig switch in-line and if so.. and it's working - what model switch do you have?