thanks for all your help and advices. It must have something to do with opening files from the sidebar and looks indeed as a bug.
As keyboard bindings in safe mode are reset on every start, I renamed my ST profile to start with a new one and only added the line for
When doing a drag & drop of a file to the editor and press Ctrl+#, the line is changed to a comment as expected.
When I open a project, click on a file in the “FOLDERS” list, select a line and press Ctrl+# nothing happens. Only when I change (add / remove) something, and the file gets listed under “OPEN FILES” Ctrl+# works.
After doing this with any file, when clicking on another file under “FOLDERS”, Ctrl+# works as expected, “comment” is toggled and the file is listed under “OPEN FILES”.
Using click / double click doesn’t seem to change this behaviour.