Like all Live events you need to wait until reencoded by NF (usually 48-72 hours):
"LIVE_STREAMING_UNSUPPORTED_DEVICE","reportingCode":"PBCS-457","displayCode":"E125","detail":"licensedManifest/playapi-457: The device is not capable of live streaming.
This has nothing to do with WidevineCDM
and has always been the case - see also here