The methodenforcement-v33-stable has a rule (only one in entire set - owasp-crs-v030301-id911100-methodenforcement) that is triggering on HTTP methods our system requires.
Found this within the online docs (https://cloud.google.com/armor/docs/waf-rules#method_enforcement)
But the CRS ruleset itself allows for additonal methods to be added within a config file -
Is this functionality not supported in Cloud Armor? If not it seems only solution is disabling entirely.