After my Unifi USG3P router bit the dust, I needed a quick replacement that offered similar capabilities so I went with the ER7206. It's been working pretty well thus far but I'm having one really annoying issue with its DHCP server. What I'm finding -- and this seems specific to Apple devices -- is that the device names are being changed to something like <devicename> (number), with the number ever incrementing.

It doesn't matter if I go back and manually change the hostname on the device, after a while the hostname will change. For instance, yesterday my iPhone was "iPhone (4)", now it's "iPhone (34)". My AppleTV devices keep incrementing their hostname. This is not a result of Apple's Wi-Fi MAC address rotation privacy features on iOS devices because I also see this on hardwired AppleTV and Mac computers as well -- the number at the end of the hostname just keeps incrementing over time. 

This was never a problem for me on other DHCP servers, and the DHCP settings available on the ER7206 console are very limited in what they offer. (And the frustrating omission of any sort of ssh access to the ER7206 make it so I can't tweak things further even if I want to.) Is this just a quirk of this hardware and I should set up a DHCP server on a different device -- or is something else going on? 

It's worth nothing that I'm using standalone mode as I don't want to have to set up a controller just for this one device -- but I'd happily set up a controller if this would give me tools to fix this problem.