You're not alone...
Over many years, In a commercial TV network setting, "home" burned DVDs tended to be problematic, even when produced on a standalone recorder/player.
For no apparent reason they would freeze, glitch, play in machine A but not in machine B, lose audio, etc. When that behavior began, and laser cleaning didn't suffice, we would simply trash the recorder. They're cheap.
You did an Express Burn and hinted that you also tried another vendor's product, so that would appear to rule out software as the cause.
Despite the "new" PC, have you tested a different burner? If THAT fails, even though it occurs at different points, one might conclude that the production itself has an effect or element that is the cause.
Report results here.