Beginner not getting beginner's luck - Flickering when animating using Polyline Stroke

Brand new to resolve. Used this video (https://youtu.be/KrsxrqUwZOc) for animating a little animation of line + bus logo going across a map. Spent an hour fighting it because initially it was creating a line of still frames of the bus following it as it moved (it wasn't deleting the old bus after each frame). Eventually realized it was something messed up with the keyframes, so I restarted from scratch and made sure I had the keyframes set for the first and final frame of the clip. That got it to work, it animated the logo moving across w/ the line like I wanted. But my issue is now that the logo is flickering for the first part of the animation, and I cannot make sense as to why. Found multiple threads asking the same question, and the only answer was to make sure spacing is set to 0.0, which it already was because I wanted a solid line on the first paint node (https://www.reddit.com/r/davinciresolve/comments/1h7wj1j/flickering_when_animating_on_a_polyline_stroke/ and the youtube comments from the tutorial I was using). Here's a quick clip of what I'm referring to. https://www.youtube.com/watch?v=ytS75dilzZg

I am (almost) certain it's not just the playback lagging, because while I am editing on a laptop and the timeline sometimes gets a little laggy, I turned on smart render cache, and it is still only lagging on the inital part of the animation and never at the end. (though maybe that doesn't work the way I think it does)

Hoping this all makes sense, I'm tired and heading to bed. Thank you all in advance, I'll answer any questions you may have in the morning. Sorry if this is a dumb question, I literally am starting my video editing adventure today, so it's hopefully only up from here.