Steps to reproduce:

1. Install Zabbix Agent 2 5.2.6 in guest Windows Server 2008R2 inside HyperV hosted by Windows Server 2012R2 or Windows Server 2019. Time sync from HyperV to guest disabled and synced by domain controllers.
2. Activate monitoring by adding this host on Zabbix Server 5.2.6 (Ubuntu 20.04 inside HyperV 2019) and standart template Windows by Zabbix agent

Result:
Monitored host starts drift time very fast, approx. 1-3 minutes difference between referenced host (Domain controller, which synced via NTP), then is synced by domain time service, but going to drift again and again.
Expected:
No time drift =)

Zabbix Agent 5.2.6 not causing such problems on 2008R2 guests. Also, guests with Windows Server 2012R2 and Windows Server 2019 with Zabbix Agent 2 5.2.6 works well and as expected. Everywhere guest time sync disabled in HyperV settings, because of domain time sync.