problem that font affects english text also

hi

I added a custom control in the arabic webfonts plugin as follows:
.header-content h3:lang(ar)

the :lang(ar) is to let the font be applied to the arabic h3 only*, unfortunately, that also prevents the english font, which set from the Divi theme customizer, from being applied.

Whatever font I change using the Divi theme customizer, it does not apply for the h3 english text.

I use the polylang plugin for multilanguage, arabic & english.

Please help!

*Reference: https://www.w3schools.com/cssref/sel_lang.asp