I upgraded 3 psa devices this week from 9.1r11 to 9.1r12, and updated the ESAP package from 3.8.1 to 3.8.2 last night. Since the 3.8.2 update, no machine with Windows Defender have been able to pass the Host Checker (AV policy). rolling back to 3.8.1 fixes this problem.
looking at the release notes for 3.8.2, PRS- 401804 is noted as resolved, it appears not to be.