Reset client - what does it really mean?

MongoDB Atlas App Services & Realm Atlas Device Sync
1

I read several topics but there is so many options so one can easily lost:

My situation:
Made breaking changes in DB schema (renamed document property), so client reset is needed. I have implemented ClientResetHandler in realm config (just for logging for now). But none of this handlers get called. Instead I have exception OnSessionError callback when I update subscriptions:

Realms.Sync.Exceptions.SessionException: Invalid query: failed to parse query: unsupported query for table "MyCollection": key "MyOldQueryKey" is not a queryable field

So far exception is understandable. The question is: How can I reset the client? And what it really means?
Do I need to make UI prompt for existing users to physical reinstall the app? Because fresh app install works as expected.
Is there any way to reset the client without reinstalling the app and in what callback stage, ManualResetFallback (never get called)?
Where does the Realm SDK stores this quarable old_field_name on the client side (because in code subscription method are updated with corect propertie name already)?

2

My config settings:

    _config = new FlexibleSyncConfiguration(_app.CurrentUser!)
    {
            PopulateInitialSubscriptions = realm =>
            {
                realm.Subscriptions.Add(realm.All<MyCollection>().Where(x => x.OwnerId == ownerId), new SubscriptionOptions { Name = "MyCollection" });
            },
            ClientResetHandler = new RecoverOrDiscardUnsyncedChangesHandler
            {
                    OnBeforeReset = (beforeReset) => { Log.Trace("OnBeforeReset"); },
                    OnAfterRecovery = (beforeReset, afterReset) => { Log.Trace("OnAfterRecovery"); },
                    OnAfterDiscard = (beforeReset, afterReset) => { Log.Trace("OnAfterDiscard"); },
                    ManualResetFallback = resetException =>
                    {
                        // EXPECTED CALL HERE (never happen)!

                        var didReset = resetException.InitiateClientReset();
                        if (didReset) // Navigate the user back to the main page
                        else // Reset failed - notify user that they'll need to update the app
                    }
            },
            OnSessionError = (session, error) =>
            {
                Log.Error(error);

                // ENDED UP HERE!!! WHAT'S NEXT?  
            }
    };