Google started declaring custom Android mod running phones as uncertified and there are some rumors that it will stop access to the PlayStore and all Google Services soon. (So many apps will stop working)

After some back and forth, google made a page where you’re able to input your Phone ID to make it certified again:

https://www.google.com/android/uncertified/

Alternatively you could use the MicroG a free open source reimplementation of the Google Services which emulate the features of the original Google Play Services. And you could use an alternative to the PlayStore:

MicroG Google Play Service Alternative:
https://microg.org/

F-Droid:
https://prism-break.org/de/categories/android/
https://f-droid.org/

YalpStoe:
https://f-droid.org/packages/com.github.yeriomin.yalpstore/

APKMirror:
https://www.apkmirror.com/

I hope you find your perfect fit. Hafe fun with your Android Phone (soon a Galaxy S10 or S11?)