Auto generated canonical URL problem

Hi,

I’m having problems with auto generated canonical URLs inserted into the page head section. The problem is with author pages. The URL is for example like this: https://domain.com/user/name+surname/ but looking at the page source I can see that the generated canonical is: https://domain.com/user/name%20surname/ and following that link (the canonical one) displays 404 not found error.

So my question is simple. Where and how can I fix this? There is any way to keep the plus simbol and not to get it replaced by the space character (%20)?

Thanks in advance.