So, I might have fixed the Sri Lanka problem or at least found a workaround (still no idea what's going on with those originals). I spent the weekend reimporting all my logos and making the kits from scratch. There is currently a Sri Lanka side shared on the academy (see spoiler) that seems to have all the kits under my name (two actually, there's a custom team).
Before downloading I would recommend, if you've downloaded my team in the past, that you delete the old logos. There's approx 30-40, I label most of them consistently, for instances like this.
Go to: Design Centre > Logo Creator > Manage Logos. Then filter and in name starts with put Sri Lanka. There's a lot but it should be quick to delete one by one. It's only modern kits, so if you have retro ones I made (mouseydread has shared those) they aren't a problem.
Would appreciate if someone could do this, at least as a test and report back any issues. Might also be wise to unlink the existing Sri Lanka team - can't confirm this needs to be done. So if you do/don't then mention, should you encounter any problems.
If this works then I'll try adding the T20 World Cup kits I made about two weeks ago.