Hey! Don't worry - this is not your fault or a configuration issue.
The "Say hi to new followers" (Follow to DM) feature is currently experiencing a known bug on Meta's side - it's been working inconsistently since March 17. Manychat confirmed this directly with Meta, and they're actively working on a fix, but there's no ETA yet.
Reconnecting your account won't help here - the issue isn't with the connection itself.
You can track updates and subscribe to notifications here: https://status.manychat.com/cmmxljn3s01ntuud42lsa7zud
In the meantime, if you want to keep starting conversations with new followers, a comment trigger can work as a temporary workaround.