My regex is not working in HTML5 forms but it works in regex101.com correctly

I am using ((ab)|(((AB)|(Ab))|(aB)))|(((([0-9]{1})|(30([\.]0{1,2})?))|([0-2]{1}[0-9]{1}([\.]0{1,2})?))|([0-9]{1}([\.]0{1,2})?)) regular expression to match if user enters AB|ab|Ab|aB and any number below 30 and that number can be floating point upto 2 decimal places.

In HTML5 form when I am clicking on submit button it says Please match the required pattern while it gets accepted in http://regex101.com I don't know why.