FW authentication will not work for JWEB access to the SRX when JSC is configured and being used.

Login to SRX interface over j-web

Firewall auth is not prompted
browser directly prompts the JWEB login page

It was identified that when both fwauth webauth and juniper secure connect are configured on the same interface, fwauth will not work.
If the traffic destined to the host ip-address configured on the LAN side interface of the SRX is through the JSC external interface, FW auth will not load.

Details of the same are available on the PR - https://prsearch.juniper.net/#!/search?page=prcontent&id=PR1714845