Title. What does delete record do? I have some problems with duplicate instance ID's which I've resolved but after restarting both the DM and the forwarder I still see some issues in the forwarder management UI.
How did you resolve the duplicate instance IDs? What issues are you seeing in the management UI?
Are all of your UFs using a different GUID?
Perhaps this old, related Answer will be helpful: https://answers.splunk.com/answers/32368/duplicate-guids-for-cloned-forwarders-how-to-correct.html
This question was up-voted today so someone else must be having a similar problem.
Delete Record: This action just temporarily deletes the client's record from the deployment server. The next time the client contacts the deployment server, the record will be regenerated. The action does not affect the client itself in any way.