Invalid full name, change of time zone

I tried to change my time zone from UTC to Asia/Tokyo but as soon as I try to change anything in my Profile settings suddenly my full name becomes invalid (even though I haven’t touched it, it’s a one word full name) and the change of time zone isn’t saved.
Also, can someone tell me what is the difference between LingQs, Known Words and LingQs due to review. From my statistics I have created 344 LingQs (in my Vocabulary I also have 344 terms) but on my main page I have surprisingly 370 LingQs to review (the yellow button), I also have 812 known words (from the statistics) but when I go to vocabulary (which says I have 344 terms) there are words that are clicked to be known (the green button). Do some of my known words belong to my LingQs and some not? How can I review 370 LingQs if I have created only 344?

Hi Narfann,
Full name needs to be 2 or 3 words so that is why it says Invalid in your case and changes can’t be saved.
A word becomes known (and it is counted in Known words statistics) when it moves from status 3 to status 4. The green check only means it will no longer be added to your Daily LingQs. That is why there is a difference in numbers of your LingQs created and Due for review.
You can learn more about LingQ SRS (Spaced Repetition System) here:

Thank you for your help!