Steps to reproduce:

1. Configured HTTP agent item with basic auth.
2. Try to execute item.

Result:
Get redirects exception ("Cannot perform request: Maximum (10) redirects followed") because Zabbix is not saving cookies from redirects when auth.

Also this problem occurs if I'm use curl without -b option (excepted 50 redirects), but when I set option -b true, then problem is gone.

This redirects may see in postman console: