C2W4lab1 - error submitting assignment

I completed the practice lab Airflow101 and when submitting the assignment, I’m getting the following message:

Our security vendor has intercepted this page.
This request triggered a filter. Please contact Vocareum support.
Gateway time-out
The web server reported a gateway time-out error.

Ray ID: 8dd7a1eab94d6742
Your IP address: 2603:8080:201:8438:1842:a6d1:e0e9:f437
Error reference number: 504
Cloudflare Location: Atlanta

I was able to submit after closing/opening new browser window.