Hairpins input with caret won't undo

I’ve encountered an unexpected behaviour while entering hairpins. In the video attached, the last keypress I did was cmd+Z. The caret went back to the earlier position, but the hairpin stayed.
dynamics input (147 KB)
(Btw, I’ve seen people embedding images and videos in the posts. Could you tell me how you do this?)

For posting videos, I’m using the free version of "RecordIt’ on Mac:

Just copy the link created by the software after recording and uploading into your post.
After clicking it, the video will be shown (on a separate site).

This kind of issue tends to be cosmetic only: the hairpin will actually have been adjusted by the undo operation, though you might not see it immediately. It is a bug, but a small and harmless one.

Ok thanks! I’ll take it in account.