I can reproduce this as well on MacOS. It seems to happen if I paste a word with a space before it. So if I paste " blah" it will do it. If I paste “blah”, it won’t. At least so far, in my tests.
Also if there is a space at the end of the title, or if you have any double spaces, there is a form of auto-correct, which cleans the extra whitespace. When that triggers, then it also jumps back to the beginning of the line.