Orbi connected computers/devices names keep changing

[fdf]

Brand new Orbi AC3000 system and encountering new problem I've never had with home networking--the names of my computers and other attached devices keep getting changes on the network (adding a number after the device name).  I see the occ error msg about shared IPs (sorry didn't write down the exact msg). They are getting assigned the same  IP numbers and have to modify themselves. What do I have to change in my config settings on the devices, or more likely on the router, to get this to stop happening? 

My equipment is otherwise a nearly all Mac household, running latest firmware and OS, etc. 

Much appreciate the assistance!

[fdf]

The specific error msg is: "The name of your computer "xxx" is already in use on this network. The name has been changed to "xxx (y)". [Where xxx was my original computer or device's name, and y is the new numerical assignment by the  network].  I know how to change it back, that's not my question, what do I have to reconfig so this stops happening?? Thx

[Roamabout]

I wonder if you have multiple devices that think they are DHCP servers and assigning addresses in the same subnet ?. What is the arrangement of your Orbi router ?. Is it in AP mode behind another router or do you have it in router mode behind another router ?

[fdf]

You may be right. I have my cable modem's output ethernet going to the Orbi, then an ethernet from the Orbi going to an 8-switch TP-Link SG-108, and then everything else connected to the switch--a Netgear ReadyNAS, a Time Capsule, an Apollo, and the 1 computer that's hard-wired (the others use wifi).  It is mainly (maybe exclusively) occuring with the hard-wired devices (the time capsule, my desktop computer, my laptop when I plug it into ethernet and leave it overnight). On the Time Capsule base station is on, wireless and network are off.

[tsig]

put your Orbi in AP mode

[fdf]

I just re-read everything you wrote a little more carefully. I don't have another router in the network (the Time Capsule is being used only for backup, wireless turned off).  I had the cable modem connected to the wired switch, and everything else that's wired attached to the 8-port switch, including the Orbi.  I also just tried taking the switch out of the network and attaching the wired computer and devices to the ethernet ports in either the Orbi or the Time Capsule (same problem with re-assigned computer and device naming).

In either case it  wouldn't make sense to put Orbi into AP mode, would it, since I need it to function as a router for the wireless devices in my network?

Thanks for your help.

[Roamabout]

If you had a working network before the Orbi (devices could access the internet, devices were getting IP addressses from a DHCP server etc) and you just want the Orbi to provide wifi service you can put the Orbi into AP mode and let the rest of the network do what it was doing before. Cable the Orbi router WAN (Yellow) port into the switch.

[fdf]

Thanks, just did that and it seems to be working.  Only thing that isn't working is that I can't seem to access the Orbi from Orbilogin.com. 

Wifi turned off on my Time Capsule, but Network turned on (appears I have to go back to using it as my router--it was starting to get a little wonky, which was why I bought the Orbi).