Getting bounce message when sending to workmail account, but the email is being received

So I currently have SES set up in the Frankfurt region, and Workmail set up in the Ireland region. I've been sending and receiving emails successfully through both for the last 6 months.

Yesterday I set up a rule in Workmail, that any incoming emails from a certain domain to admin@domain.ch trigger a lambda function. Upon doing this, however, any incoming emails to info@domain.ch now gives the sender the notification "This message could not be delivered due to a recipient error. Please try again later.". Now, after removing the rule, this issue persists and I can't get it to go away. I've tested sending from hotmail and gmail, both give the error. I have no incoming rules set up in SES either.

In case it helps, I logged the event in cloudwatch (anonymized here): { "accountId": "YYY", "organizationId": "YYY", "traceId": "YYY", "eventTime": 1706304423353, "event": { "spamVerdict": "PASS", "recipients": [ "info@domain.ch" ], "subject": "Test", "messageId": "YYY@mail.gmail.com", "eventName": "ORGANIZATION_EMAIL_RECEIVED", "from": "anonymized_incoming@gmail.com", "dmarcVerdict": "PASS", "spfVerdict": "PASS", "messageTimestamp": 1706304422445, "dkimVerdict": "PASS" } }