Currently, on my system, comments default to being directed left-to-right. To change this, I'm not supposed to edit a full-blown style; instead, I choose "format all comments" in the drop-down menu each comment has.
Well, the thing is, the "format all comments" dialog doesn't include the comment paragraph direction (LTR/RTL). Which it probably should.
I confirm it with
Version: 18.104.22.168 (x64)
CPU-Threads: 4; BS: Windows 10.0; UI-Render: GL;
Gebietsschema: de-DE (de_DE); Calc: CL