After upgrading your Rails version, "forgot password" is no longer working for you - you can send the forgot password link, but when you follow the link it always says it's invalid.
We encountered this when upgrading to Rails 8. The only thing we found in the release notes or changelog that appeared related was about 7.1, but we were on 7.1 for a while, and did not encounter the problem with 7.1 or 7.2 - only when we upgraded to 8.0.