IsSoftDeleted is a provisioning engine virtual attribute, evaluated only at runtime during provisioning operations, currently as of me writing this post, there is still an Entra issue with the payload and attribute mapping to "Active". When it is sent to active it should be a Boolean (true / false) but currently Entra will send it to the remote platform as a string ("true" / "false"). Option one have the remote platform modify the Active field to accept strings, option 2 use the SCIM compatibility flag in your endpoint URL.