I just came across an issue at a customer that migrated to Dynatrace Managed 1.252.
Seems that the application detection rules got a new Settings 2.0 API-Endpoint and that changed the content I get when using the config api v1 endpoint: The name field does not contain the name anymore but is replaced by the entity id of the rule. This renders the config as code tool (Ansible) unable to detect already created rules. So we quickly recreated all rules several times until we hit the 1000-rule limit.
When trying to insert a new rule with the old api I can see it is working as expected. So this looks like a data-migration issue.
Can someone from Dynatrace confirm this? Otherwise this post is hopefully warning someone else...