Some devices cannot download my app from Google Play due to compatibility issues

I have published my Flutter app to Google Play Console for testing.

Recently I noticed that **some users cannot download the app** from the Play Store.

When they try to install it, the Play Store shows a **compatibility message**, such as:

"This app is available only for your other devices."

However, the strange part is that **other phones can download the app normally**, and only some devices show this compatibility issue.

My app details:

* Built with Flutter

* Uploaded as an Android App Bundle (.aab)

* minSdkVersion: 21

* targetSdkVersion: 35

* Currently in the testing track on Google Play

I am not sure why certain devices are considered incompatible.

Has anyone encountered this issue before?

Could someone help explain what might cause this compatibility problem?

Thank you very much for your help!