Using Safari Version 14.1.1 (16611.2.7.1.4) on Mac OSX 11.4 (20F71) when my Angular SPA POSTs to oauth/token during login Safari is reporting 504 Gateway Timeout.
The error only occurs when the POST occurs from the service worker on the SSL enabled site. Running debug or production builds locally works without error.
On the same laptop using Chrome, Firefox, or Brave the same application logs in the same user without errors in dev and via https. Safari on iOS also logs in correctly.
Any ideas?