buddy Phew, it seems I'm not the only one and it's a known issue since beta.
It seems as if the issue in the Reddit thread is closely related to the issue you are experiencing, but that doesn't mean it is exactly the same issue. No GrapheneOS user ever ran exactly the Google Android Beta release which appears to have triggered this issue for a small number of users, because Google's Android is always different from AOSP. Similarly, a while ago in the press there were articles about a so-called "ransomware bug" with multiple user profiles in official Google A14 release, but no GrapheneOS release ever shipped the same Android as Google did, and it appears that no GrapheneOS release ever had the multi-profile data-loss bug. Thus the similarity of symptoms does not conclusively prove that the cause is the same, thus that the solutions must be the same.
buddy Hmm.. I prefer not to grant root access or factory reset.
I believe adb root will fail on production releases of GrapheneOS, in which case that is not an option.
But in your situation there might be a third option. If the reason your device is having the problem is not the package-manager bug that briefly occurred in Google's A14 beta program, but instead that permissions were removed from com.android.intentresolver, putting those permissions back might fix the problem for you. Thus... on your device, are any permissions removed from IntentResolver / com.android.intentresolver? Is "Open by default" turned on?