As I don’t agree with the assumption that AutoCorrect is relevant here, this cannot be an answer.
I just want to attach an example demonstrating some of the aspects mentioned by my comments to the question itself and to the previous answer by @Kruno .
This example was made with UI-language English (UK) and locale setting English (UK) as well. I was doing this on a Win 10 system in German language located in Germany.
There was some version that had bad AutoCorrect entries like :1: for clock symbols and those hit when entering times in Calc if AutoCorrection was enabled. I don’t remember which version and when it was fixed to :1 h: etc.
@erAck, your comment essentially answers my question! Thank you! It looks like I should just remove these entries. (I’d upvote your comment but I’m not allowed to do so.) But, you mention “if AutoCorrection was enabled.” Do you know how to disable it? That would technically solve the question I’ve posed.
@dcmertens: As @erAck mentioned the “evil” entries in the replacement table were only present in a few older versions (if not just in one). I personally never noticed them. You may consider to update to a more recent version of LibO.
To disable the usage of the replacement table is an option under
Tools > AutoCorrect Options... > tab Options.