I've been using Phonetrack for a long time with no issues, but lately, it no longer seems to send my location in the background. It will often show the green location indicator for a while - several minutes - but no location will be sent to the server. Sometimes, it doesn't even do this. Either way, as soon as I open the app, it sends my location to the server.
I have tried enabling exploit protection compatibility mode and sending the app through split tunneling with my VPN, but these did not help.
This issue seems to coincide with the recent changes to the app battery usage menu, so I wonder if it has something to do with that GrapheneOS update. I do have it set to allow background usage.