Some apps don't work right with the new ios 18 update

I made the mistake of updating my phone to the new ios 18 because I've never had any issues with past upgrades.

Now, the apps I use to track my cats through Petfon and Tractive no longer work properly. The Petfon trackers will no longer sync with my phone, but they will still sync with my old android phone. Tractive still works, but when I was outside, it showed me constantly moving when I was standing still.

I wrote to Petfon and hope they will have a fix for this. I so regret updating to ios 18.