I had "invalid host entry" issue and corrected it by running diagnostics feature within Cisco AnyConnect.
Path: Click on the Settings icon (gear) in bottom left of login screen. From Settings screen, click on Diagnostics button on top right of screen. This launches Cisco Diagnostic and Reporting Tool (DART). Follow prompts to run the diagnostics.
I did not need to change any configurations. Just running the diagnostics tool fixed the problem.
I hope this helps... Good luck!
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