Multiple duplicate DMs from Mastodon

I keep getting multiple duplicate DMs from Mastodon users. Is this a glitch on the MB side or the Mastodon side?

Sounds like a glitch to me. I don’t think I’ve seen that, but perhaps it happens if someone edits their message on the Mastodon side? If the DM identical?

The DMs are identical. If they were edited I’d kind of get why it was happening, but they’re not. It’s odd.