Can't connect RoseConnect app to RS201E

My roseconnect app on IOS 16.1.1 refuses to find the RS201E unit.

My woes started when I yesterday updated my wifi network to a TPLink Wifi 6E system. I will create a new support thread on this particular issue, since the Rose unit is the only one in my house that can’t get a working connection to the wifi. Due to this however, I had to revert back to my old network, where the Rose unit has been working fine until now.

Since then, no matter what I do, the app CANNOT find the unit. I’ve tried the app from my phone, from my wife’s phone, from my MBP - nothing. It’s not visible, even if I try to connect it directly with the IP. Everything’s on the same network, on the same subnet, using the same access point. I can ping the Rose device just fine from my macbook. The Rose unit has no problems connecting to the network either. I can even stream music to it using Spotify connect from the same phone where the app is installed on.

The app however can’t find the unit no matter what I try. I’ve done a factory reset of the Rose unit. I’ve reinstalled the app on my phone too many times to count. It’s just… gone.

I will say that the Rose unit had a firmware update yesterday, so unsure if this can have something to do with it.

Rose system version 4.6.
Rose system IP: 192.168.70.74
Iphone IP: 192.168.70.69

It would also be useful to know which port the Rose unit is listening to to connections on, so I can verify it’s accessible.

Edit:
After a few hours of troubleshooting I think I’ve figured out the issue. When the Rose connect app last worked, it was on a 192.168.1.x subnet. For the hell of it, I switched back the 192.168.70.x subnet to 192.168.1.x - lo and behold, it could find the Rose unit again. Either there is a setting somewhere which persists through app deletions and factory resets, or it’s to do with that the app can’t handle a 192.168.70.x subnet.