I have a FP4 with Murena.
A transit app I use stopped working and gave me a warning “app won’t run unless you update google play services”
When trying to do so an error came up after downloading it from the murena app store.
Saying there is a “signature mismatch”
You are running /e/OS. This means you don’t have the genuine Google Play services, you have microG mimicking Google Play services so that Google-dependent Apps have a chance to work without the genuine Google Play services. There’s the mismatch.
microG is a system component in /e/OS, so it gets updated along with /e/OS updates.
Such incompatibilities between Google-dependent Apps and microG can always happen. If you really need this transit App to work 100%, you would have to consider other OS options.
I have /e/OS 3.1.1 install and I still have the notification every time I launch the app. But the app works without any problem. This is a very minor inconvenience.