No email notifications from z2m forum

Lately I don’t receive email notifications from this forum any more.
I checked my settings and all are the same like in the ha forum. The thing it works fine with ha, but doesn’t work with z2m.

What can I do? Does someone else face the same issue?

I changed my email address to another one and it works fine with that one.

Have to mention that it definitely worked before with the old address. Also I use this „old“ one in ha and works fine there.
That’s weird.