Welcome to the forum. Yes, turning off hardware acceleration does resolve some issues that arise for PD9 users.
The preview window is just that - a preview. It is consuming varying amounts of CPU, depending on the resolution selected, so sync problems are not unusual, particularly at high resolutions, and particularly if the computer is underpowered.
Hope this helps. Have a great day.
Regards,
-Phil
Windows 10 Pro x64
Dell XPS 8930
Intel CoreT i7 (4.6 GHz)
32 GB DDR4-2666 RAM
1 TB PCIe -x4 SSD
NVIDIA GeForce RTX 2060
PD14 Ultimate x64, 4207
CD4 Ultra and AD6 Ultra
Bleeping Computer Malware Response Instructor