strong tag don’t work

Hi everyone.
I would like to insert strong words into the various blocks of text but I can’t and I don’t understand why.
I use the montserrat font but if I indicate it I select the word and say “strong” it changes the font and uses the color of the primary color the same as the links. How can I make sure that the bold actually corresponds to the same font with the same color as the rest of the text but just a little bigger?

thank you!!!!