How to create filter with special characters?

Hi,

I have several intitle filters that do not seem to work when special characters are in it.

For example:
intitle:kingdom = works
intitle:'kingdom come deliverance' = works
intitle:'kingdom: come deliverance' = does not work
intitle:'kingdom-come deliverance' = does not work

I read https://freshrss.github.io/FreshRSS/en/users/10_filter.html and encapsulating phrases in quotes do work so long no special character is inside.

Can advise?

Thanks