Importer - CP error with IPv6 subnets

[tpurschke]

 FWORCHAlert - "source": "im port", "mgmId": 71, "title": "import error", "description": "[{'import_errors': 'ERR-ImpMain@import_nwobj_maininvalid input syntax for type cidr: \"5002:abcd:1234:2800/53\"'}]", "alertCode": 14, "severity": 2, "import_id": 79, "mgm_name": "cp test mgmt"
2024-07-02T12:01:41.410560+02:00 fwoserv1 fworch-importer-api:  2024-07-02T12:01:41+0200 [INFO ] [common.py :complete_i: 310] import_management: import no. 79 for management cp test mgmt (id=71) threw errors, change_count: 0, duration: 57s, ERRORS: [{'import_errors': 'ERR-ImpMain@import_nwobj_maininvalid input syntax for type cidr: "5002:abcd:1234:2800/53"'}]

This is actually a malformed ipv6 cidr. unclear how this could be entered in the first place.
Could this be an interface IP?