Duplicate donations

I have a site that just in the last few weeks has gotten a bunch of duplicate donations that is resulting in unhappy donors, bank disputes, and refunds being issued. Obviously not great for a small nonprofit... Anybody else seeing this? I'm trying to figure out if it's a matter of lag time and donors actually donating twice or some other issue.

It seems to correlate at least roughly to the most recent upgrade to CiviCRM Stripe 6.5.5.