This issue is fixed in fixed in samba 4.5.3 with PCS OS 8.3R3 and up.
To confirm if this is the root cause for high CPU, a system snapshot with debug logging with AD auth event codes will need to be taken. To have Pulse Secure support assist with this, open a support case and refer to this KB article.
Otherwise, if this option is enabled, it can be disabled and the system can be allowed to run for some time to confirm that the CPU usage decreases.