segmentation: break after single letter + dot at start of paragraph

I have here a Q&A file which starts each question/answer paragraph with either Q.<space> or A.<space> . In German this would be F.<space> or A.<space> .

I want the "Q." / "A." in a separate segment.

To be thorough, "Q." / "A." are also surrounded by formatting tags (bold), but this shouldn't interfere with segmentation as I understand it. ok?

 

I tried several segmentation rules (the most specific being [AQ]\.\s with and without ^ for start of line) with no success. I also experimented with the full stop rule.

Usually I'm pretty firm on the regex front but this one eludes me. Any (verified) ideas anyone?

Always optimistic
Angela