Error "Grant type 'http://auth0.com/oauth/legacy/grant-type/delegation/id_token' not allowed for the client" after saving settings

We tried to patch our new client to work with the Firebase addon like this and it DIDN’T WORK (ADMIN is an “all-allowed” token)

curl -X PATCH \
 -H 'Content-Type: application/json' \
 -H "Authorization: Bearer $ADMIN" \
 https://****.eu.auth0.com/api/v2/clients/D*** -d\
 '{ "grant_types": "authorization_code","implicit","refresh_token", "http://auth0.com/oauth/legacy/grant-type/delegation/id_token"] }'

--> {"statusCode":400,"error":"Bad Request","message":"Invalid grant types: http://auth0.com/oauth/legacy/grant-type/delegation/id_token"}