Notification category missing

Recently got a Note 10. I installed the Garadget app and it is working, just not pushing notifications at all.
I also have a Galaxy S10 & S6 on the same account and that is working and pushing notifications instantly.
So I assume it’s not the Samsung notification delay bug with doze mentioned on this forum or many web pages.
I have logged out and in many times, deleted cache uninstalled, reinstalled all to no avail.
Checked all settings with the S10 are the same.
Interesting thing is as the S10 & Note 10 both run Pie when you look in the app notification setting page
the S10 under Categories has garaget_channel_lite option with toggle set to on and sound & pop up selected but the Note10 has under Categories “This app hasn’t sent you any notifications” message.

Has any one else experienced this issue or know of a fix?
I’m trying to avoid a factory reset at this stage

When re-installing the app, try disabling auto app data backup.

Thanks Denis, I gave that a go and followed all parts minus the keyboard words as the guide was a bit dated and I couldn’t find the relative parts in Android Pie. I don’t think it’s related anyway…
Unfortunately I still don’t have notifications working on the Note10 and the channel is still missing.
Can’t work out what’s suppressing it all other notifications from apps work as they should.

Resolved with a factory reset and then setting up phone from scratch not using the google account backup data.