Understand. That is how it should work. Example: I on my home network. Openspot4 and M1KE are connected to my home network (192.x.x.x). Sharkfr.link on my phone, which is also on my home network has found both devices can connect to either. Works great.
I leave my house. Turn on my phone hotspot. NEW NETWORK NEW SUBNET. Openspot4 and M1KE both connect to the phone's hotspot (172.x.x.x) as the phones network is in the connect. Phone, Openspot4 and M1KE are all on the same subnet. I open up Sharkrf.link (web page or app) on the phone and select the Openspot4. A blank web page opens on the phone with the URL address for the Openspot4 of my home network. The M1KE also shows the URL address for the M1KE that it had on home network. If I wipe the CACHE of Safari it will find the devices..... However, I have to put in their UID's again as new. SharkRF.linnk is not up the "new" network. You should be able to test this using a WIFI network and a phone hotspot, or two different WIFI networks.