HI DTS,
Welcome to the forum. I tried to duplicate your specific problem but was unable to.
If I understand correctly, your saying the video was produced with the grid lines visible. When I used the sample files, grid lines showed up but when I produced the lines disappeared. Viewing the produced file, nothing but the video showed.
Maybe some of the other volunteers (editors) have ran across this problem so hang in there.
Could you post as an attachment, use post reply, a screenshot of your full work space, that may shed some light on the problem. Sorry for not being much help.
Dave
HP Envy 17
Win10 Pro (64-bit) Intel i7 Core - 4510U @ 2.00GHz 2.60GHz
16GB ram
PowerDirector 11 Ultra 64-bit ver. 11.0.0.3625
Cyberlink Power2Go Deluxe 7.0.0.1827
PowerShot SX40HS
Canon Vixia