Checkbox not working.

2 checkbox is working but This 3 Checkbox Can’t working. please tell me how can I fix it.
2019-09-17%20at%2011-43-54

I can’t understand this logic. please Solve this logic. how can I Added Lower Case + Upper case + and Number text Random generate.
2019-09-17%20at%2011-44-32

i think you cant use 3rd and, and in each number list you must have to use from 1 to length of list of any list which you use, you cant use text box instead of list, like my blocks of my project
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