Fade problems with .ass file using VLC media player to hardcode

[Silverleaf16]

So I can successfully hardcode my .ass subtitle file and produce an mp4 video, and all the stylizations and effects are included, but there’s a problem with the fade effect. My fade outs are quite long (2000+) and those will start to fade correctly but then cut off right near the end, as in the last part of the fade isn’t gradual. Is there any way to fix this? I’ve tried exporting the subtitles in .srt, using the clean tags, fix styling, and transform framerate. I’ve tried encoding the video using h264 & mpeg4(this made the video glitch however) and I don’t know what else to do. The length of the fades don’t exceed the length of the lines, so there shouldn’t be a problem there. The shorter fades (2000-) work just fine though so something’s still wrong with the longer ones. I’ve even trying playing my hardcoded video using different media players to make sure it wasn’t just one being faulty, but the problem persists.