White Background in GIF with Transparent Artboard

Hi! I am currently using Photoshop CC 2021, although I have produced the original transparent gif in CC 2020. I converted a video timeline GIF to a frame animation, and after exporting I noticed a stray pixel. I put the GIF on a transparent artboard to resize it proportional to the GIF and clip the pixel out, without having to erase the pixel from all of the frames. After adding the artboard, there is a single frame at the end that glitches out with white bars on export. This frame just shows as the artboard within the file. When I click on other frames in the timeline, the artwork completely disappears from the frame. I am not entirely sure how to fix this issue. I am running Mac OS Mojave.