I have the same issue with Win7, so I'm going to try this at home when I get the chance:
This article suggests looking at drivers, interfering Bluetooth devices, using the Windows Troubleshooter, and a variety of other areas of interest. It's designed for Win10, but most of it should work for other Windows versions.
I always hesitate to download "driver managers", like this article suggests. The one's I have done in years past generally seem to be more like "advertising managers." At minimum, the website that shows technical knowledge to fix your computer by downloading driver files or dlls wants you to download it's software first. That always screams "malware" to me, so no thank you.
BTW, part of why changing the audio to -300ms is because the brain sometimes can meld the audio with the video it gets into a single "stream" of input, as long as the two are somewhat close to in sync (not the boy band, however). By getting the audio and video at least close, your brain does the rest.
Do a Find on "auditory" to get to the relevant section.