Maybe it’s a problem with the beta, but I suspect the problem lies somewhere else.
Unfortunately I don’t have screenshot from all occurring issues.
Sometimes the app will prompt the wrong tone (see screenshot).
(I tend to check up in Pleco). A variant of this issue is the occasional 不 marked as 4th tone, even if the next word is in the 4th tone as well.
Sometimes words are missing in the Pinyin
And sometimes the Pinyin spelling is wrong as well, no screenshot, though.
This happens just with a tiny fractions of the words in my list. It seems it occurs rather with newer words.