During the initial release of Pulse Secure Linux, Host checker functionality is not present in the 8.1R7 version of Pulse Secure Linux client. If a VPN connection is terminated by the PCS server, and Host checker is enabled on the PCS for the user role or realm, the user cannot connect.
To resolve this issue, please upgrade the Pulse Secure Linux to 8.2R2 and above. For more information, please refer to the 8.2R2 release notes
If upgrading the Pulse Secure Linux client is not possible, this limitation can be mitigated either by disabling Host Checker on the user role/realm or by creating a new realm and role without Host checker enabled specifically only for command line Linux users.