Notification problem

Hi all,

I’m using K9 Mail on my mobile phone (ASUS A007).
I configured the app with the same settings as in an other phone (Moto G5) and I can send and read E-Mail.
My problem is, that when a new E-Mail arrives, I get don’t get a notification. On the Moto G5 the notification arrives in a couple of seconds.
Does someone have an idea what could be the problem?
K9 Mail is in the latest version from Google Store (5.600).

Thanks a lot

There’s another post that provides a list of possibilities to investigate for missing notifications:

See if any of these help.