Emoticons / emoji in Email subject together with german umlauts not working

Hi together;
want to use emoticons / emoji in the subject and have a problem with german umlauts like ü Ä ö …

when i use emoji symbols together with german umlauts (here the Ü) in the subject then it´s not working - e.g.:
=?utf-8?Q? =F0=9F=92=A5?= HALLO =?utf-8?Q? =F0=9F=92=A5?= Umlaut Ü im Betreff

without umlauts in the subject everything is working - e.g.:
=?utf-8?Q? =F0=9F=92=A5?= HALLO =?utf-8?Q? =F0=9F=92=A5?= kein Umlaut im Betreff

See both results in attached picture.
German umlauts without emoticons / emoji are working.
I´m using phplist in version 3.3.1 installed on my server.

Hope that there´s a way to use both in the subject.
Thanks for Help


To clarify: these non Latin characters are only mishandled in campaign subjects not campaign bodies? If so possibly different encoding functions are being used on these separate text bodies and fixing that should be straightforward.