It could be that it isn't coded well for Android, or specifically for Android 11 (from what I understand, Google changed a lot of coding things with Android). That's Android's main problem really, it changes way too much and way too often between versions, making it a moving target for developers. Android 11 and various changes broke a lot of apps, even the OS itself was broken in several ways (like a touch issue on the lower half of the screen just fixed at the beginning of last month), and now they've announced Android 12 available for developers (kind of like early/beta), so they haven't even fully worked out the kinks in this version before the next one.Sorry to hear that app gave you a hard time! It seems to work on this end of the country. Whenever i remember to turn it on anyways.
But anyway, a lot of reviews on Google Play store mentions issues with finding and maintaining GPS, and that's on all different makes of phone and versions of Android.
I can say the app was super easy to use and setup, it didn't crash or anything, and would be cool if its basic function didn't get so easily broken.