PMs showing double

[Canoe]

In PMs, old messages are showing double. Each appears twice (picking one to delete, both entries disappear).
Recent messages appear once.
Anyone else seeing this?

p.s. it's been this way for many weeks.

[Token]

Confirmed.

And I ain’t started drinking yet for the day. Sheesh.

[trilobyte]

Is this happening on new/recently received messages (within the last few months), or on older stuff. There was a known database issue last fall that caused all kinds of duplication, as well as the delete one and it kills both behavior. I haven't seen that happen since the end of last year, when the tech team did some additional maintenance. If it's more recent, please ping me privately as I'd like to get a screen shot of your message list (I don't need to see the actual messages), thanks

[Canoe]

Not recent messages. Recent messages behave as expected.
I don't know the cutoff date.
All duplicates have a 2017 or earlier date, but that could be co-incidence.
Earliest that doesn't have duplication is from June 2018, but there's a gap without any PMs, so that's not likely to be very useful.
Going to the oldests PMs, they're from 2011 and appear in the index twice.

It appears to be display, not message duplication, as selecting one of the two index lines and deleting it results in both index lines being gone. But perhaps it is data duplication, and the selected index line references both copies. No way I can tell from here.
I'll get a screenshot.

[trilobyte]

If the duplicates are 2017 dates, no need for screenshot. Mark em as read and ignore.

[Canoe]

Are they using up my allotment of PMs?
As in, is each counted once or is it also counting the duplicates...