Sorry for all the edits...I meant sms & mms.

I meant to add that I don’t have any other Apple devices to check.

I turned on Messages in iCloud a few weeks ago. But when I drill down to conversations (through storage, as you described), less than half of my iPhone 6s’s conversations are there. Any idea what could be going on? Btw, for reasons I won’t go into here, I am currently using sms & mms only — no iMessage. And I don’t…