iCloud Message syncing issue after changing settings

I received a new iPad months ago, and was messing with the settings and turned my iCloud messages off then back on. When doing so, deleted messages from 2019, a thread from 2020 and a week worth of deleted messages from 2023 all reappeared. Any idea why this would happen? I’ve had two other phones between 2019-2022 and never came across this issue.

[Re-Titled by Moderator]