I'm also having trouble with a list. I finished hsk level 3 and moved to level 4 but it doesn't seem to add new characters. The hsk 4 list doesn't appear in "my list" but when I go to "textbooks" tag and pop it up it shows as 5% loaded.
In "my list" the 4 lists completed (101 skitter, hsk 1 to 3 appear correctly tagged as completed. Hsk 4 doesn't' appear at the top. Instead their is a message saying I'm not adding any character from any list.
But in fact characters are added!

I was probably too fast on the bal... All is ok now.