Why does my code work differently in the compiler ?

Question

My code should show number of digits in a string. When I run in Visual Studio, and write input like “hdxh1” it shows that this string has 4 digits,but when I run in any online compiler it shows rightly like output 1. Who can view and fix it?
https://code.sololearn.com/c92q9t9jxkNO/?ref=app