Match regex operator broken?

Hello community!

The RegEx expression .* should match anything. While applying this expression in combination with the operator =~ in the New Silence area “Affected alert instances” stays empty. There are definitely alerts firing and these can be matched with the full alertname.

works fine
alertname=FULLALERTNAME
alertname=~FULLALERTNAME
alertname!=WRONGALERTNAME
alertname!~WRONGALERTNAME

do not match
alertname=~.*
alertname=~FULLALERTN.*

Grafana 9.0.2 OSS, Alertmanger 0.24.0

Kind regards