Odd bug on regex

using very latest wappler, windows 10, xamp local install.

I have a login form and a register form. Both work just fine, apart from a weird bug in the handling of regex.

Both my forms have the exact same regexp:

^(?=.*[a-z])(?=.*[A-Z]).{8,}$

I have checked and copy pasted to be sure, both have the same.

Now on the register form, I can register and use a special character.

When I go to login if I enter a special character it says numbers and letters only, despite it being the same regex used on register that accepted the special character.

Has anyone else found this? It causes problems because people create their account and use special characters in their password, then of course cant login.

thanks
Darren