Email alerts condition doesnt work

Hey everyone,
so i created an alert which should send me an email if the serverity is higher than 5 (could be x).
If i say it should send me a mail “always” it works perfectly and i get a pdf file with a nice summary.

But if i change the condition to “serverity at least 4.9 (could be x)”, it doesnt work anymore and i dont get a notification.
Why is that? Of course my condition should be true, i scanned a testServer where the serverity is 10.0

I cant explain why it behaves like this.

best regards