Architect Set Variable failing with 401 on ServiceNow incident update

Just noticed that the webhook.execute node in our Update_Snow_Incident flow consistently returns 401 Unauthorized despite the Authorization header containing a valid Bearer token from the OAuth2 Data Action. The payload targets api/snow/instance/table/incident and includes the correct sys_id. Verified the token is not expired via curl. GC Release 2024-12. Any ideas on why the ServiceNow REST API rejects the header structure generated by the Architect Data Action?