Installing microG on Sailfish OS

Hi,
not sure if anyone can help here. I had this Postfinance app (banking app) working without microG on an Xperia 10 III and after an update of the app it does complain about the device being rooted.
That’s where I installed microG in the hope that it could help make it work again but after following this thread, microG is installed but the Postfinance app still complains about the device being rooted.
Am I out of luck and it just won’t work whatever I try?
Does the banking app have a folder maybe with some settings files in it that I should erase before reinstalling it?