We have had several integrations stop working. We are now receiving a 500 error when testing a payload with POST webhooks, but the normal Jenkins webhooks still receive 200. Same results when testing with an actual pipeline. With the two webhooks configured for the same endpoint only normal Jenkins webhooks are able to fire off a build. Since the documentation says that the older webhooks are deprecated, we would prefer to stay away from them.  

The only thing message that appears in the Jenkins log when POST webhooks are used is:
Jan 06, 2023 3:39:42 AM INFO com.cloudbees.jenkins.plugins.BitbucketPayloadProcessor processPayload
Processing new Cloud Webhooks payload

Please let me know if I can provide any more detail.