I've got four Pro devices with three hardwired back to a switch which then connects to the router point.
In the configuration that I set them up in I have no issues and I'm getting 900Mbps plus from each point. I've tried to move one of the points to a different room but still hardwired back to the switch but after a few minutes I'm only able to get around 90Mbps from that point. If I move the point back to where it came from its giving 900Mbps plus again.
Lets assume the cable is fine, as it was serving a previous gen point without issue, so is this some kind of known issue? Does the point need resetting in the new location?
They do not need to be reset to move from one place to another. But, any time I see something like this, with a speed coming in just under 100Mbps, I have to focus on the Ethernet connection. I know you said not to assume that is the issue, but unfortunately, that is the leading candidate in this case – it may only be negotiating a 100Mbps connection rather than the 1Gbps that uses all four wire-pairs. Sometimes this can happen just as a result of slight differences in Ethernet ports between devices. I would try removing and re-seating that cable a couple times, and I would try connecting a laptop or something with an Ethernet port to verify it is negotiating 1Gbps. You may even want to try re-seating the other end of the cable at the switch, or try running a long cable (temporarily) through the house just to bypass the questionable cable.
It may well be the cable but I wanted to check if it was a known issue first given they're new and do have issues.
Interestingly, I did try removing and reseating the cable from both ends, which increases the speeds again but it soon reduces back down to around 90Mbps which seems odd as the cables aren't being disturbed. So it seems to be initially negotiating at 1Gbps but then, for whatever reason, reduces down to presumably 100Mbps.
I have some ethernet testers will just double-check that it's passing the continuity test.
I have seen cables that are making marginal connections drop back to 100Mbps speeds on occasion, so it's not impossible. If you have a spare 5-port Ethernet switch, you might consider putting that at the end of the long run from your core switch and then connect the Nest WiFi Pro unit to that. Even better if it has LED indicators that can show connection speeds for each port.
@SteveyJ just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.
I appreciate the help, Mel and MichaelP.