I would kindly ask you to reconsider your review.
First of all, the converter converts ONLY the config to the new format and update strings from legacy format to MiniMessage. That being said, version specific values aren't changed, for example Materials - which were the main cause of your issue, you had 1.12 materials on a 1.18.2 server.
Secondly, the problem you were facing wasn't reported by anyone because 50% of it was an user error - as mentioned above, you were using the wrong materials for your server version -, and the second 50% was cause by the GUI library I use - which I fixed while we were discussing.
Third, the version of the plugin is a "snapshot", meaning that problems can happen. Nothing is broken by intention, but with good communication everything can be repaired. You mentioned that you were going to test the plugin on a different game version, but in fact, you were talking about your client version, which has nothing to do with the functionality of the plugin
https://imgur.com/a/uGdZpu4
Though, I would like to thank you for reporting the error and I wish we could have done this in a better way.