starting with ONTAP 9.12.1 DP\TDP snapmirror engine is deprecated
https://kb.netapp.com/onprem/ontap/hardware/What_is_the_ONTAP_version_requirement_of_TDP_snapmirror%3F
Note: Beginning with ONTAP 9.12.1, transisition data protection (TDP) relationships are no longer supported for 7-mode volumes. Use CIFS or NAS tools i.e., (Robocopy, Xcopy, XCP, Rsync, or NDMPcopy) to transfer data to CDOT Clusters then use SnapMirror technology