Gif transparency inconsistencies.

Recently bought Discord nitro on a whim, started tinkering with Gif avatars and whatnot and noticed, transparent gifs have... well odd properties.

Some would play just fine, others would play and have one or two frames go white or black, others would have full white or black backgrounds where there was transparency.

I'm not knowledgeable enough to know whether or not it was the software that it was created in has any settings for such things on export, but I'm curious to see if anyone has found a software/export settings combo that works to make certain the gif will have a properly invisible background.