Why are many KNOWN words not accepted in puzzle or as bonus words?

Wordscapes has increased the number of acceptable words fairly recently (mid 2020) presumably by referring to additional dictionaries. However there are some valid words still missing and others coming up as valid which no-one other than a dictionary compiler would have ever seen.

What about the word nee (formally known as)

There are also plenty of dictionary words that it won’t except. Like, the adjective “uber”. The game mistakenly assumes that you’re referring to the company Uber, which then would be a proper noun. However the word “uber” has been around much longer than the company, so it should be accepted as a legitimate word since it is, in fact, a legitimate word.

Dais is a word that I have played in several Words cakes puzzles but was never accepted as a bonus word. Just today, while it was not in the puzzle I did get the bonus for playing it. I commented about it and someone who had more brilliance than I said he plays the word dais all the time and receives the bonus. I am now wondering if bonus words are different for each player based on the level they are at currently.