I have checked the setting and it is and has always been set to forever when it comes to settings-messages-message history. Yet since I upgraded to ios 18.1, my messages have started to delete by themselves every other day or so. In the last week, I have had to go into the recently deleted and recovered the messages at least 3-4 times. It does not delete all my messages just random messages from whom I have messaged recently. I have message that have been there for at least 6 years and those are not deleting. Please help before I lose some valuable messages.

Can someone confirm this is supposed to be happening after all these years. I have noticed that now when I delete the messages from my Apple Watch (IOS11) they are now deleting from my phone (IOS18). I was glad I noticed and was able to recover them but I almost lost some impoRyan messages. I did do a test and confirm this is true. But the question is, is this supposed to be happening and if so is there a way to disable only this sync? I like to try and keep the messages icon on the watch clean since when I read the messag on my phone it does sync read on the watch and leaves the unread number on the icon.