L-Lower-3rd Title darkens Video??

I've dragged and dropped the L Lower 3rd title into my timeline and edited only the text. During playback or when the playhead is over the text box on the time line, the video darkens a bit during the length of the text box, almost like a vignette. I've been through both text and video options for the text box and nothing helps. Super annoying. Any advice? Thank you.

The entire raster darkens, or only the lower third?

The entire raster darkens, or only the lower third?

The entire raster darkens for the duration of the text box.

The alpha channel is probably not truly black in the area that supposed to be transparent.

OK.

This was a title preset included with the program?