push notifications not working on either android 9 or xiaomi mi 9 se

[JohnMTu]

Hello,

i fetched new xiaomi phone with android 9.x but cannot get push notifications working.
If i send same config to old samsung phone with android 7.1.2 then notifications are working like a charm.

could it be issue of app with newer android? On both it's app 2.5.6. Already tried to delete all app-data and import config. No success.
Or is that somehow know issue for xiaomi devices only?

According to application permissions screen, it has never sent any notification.

thank you