Aegisub has frame accurate timing options, no idea which options you're using to limit yourself this much in terms of accuracy.
Use the left/right arrows to go frame-by-frame in the video, while on the last frame the subtitles should be displayed use Timing-->Snap End to Video. Vice versa for Snap Start to Video.
I loaded your subs into Aegisub to confirm and it was no issue fixing the timing this way.
Also, that video has proper subtitles shared here:
https://f95zone.to/threads/blendy-collection-2021-12-10-blendy.71786/post-13839722
Pixeldrain