Recurring payments coming into CiviCRM with wrong date (Dec 1969)

I updated a Drupal 7 site from an earlier version (5.0 I believe) to 5.3.2 last week. Things in general seemed okay, and I updated the webhook accordingly as well as updating the Stripe API version in their account. I'm told that recurring payments are not reporting back into CiviCRM -- they are charged correctly in Stripe but do not appear in the contact's CiviCRM record.

These recurring payments may have been set up years ago, as they have been using this extension for a long time. If recurring payments seem to be working okay in general, is it possible these plans are just missing some info in the database from one or another upgrade over the years? How would I start to track that down?