Bold font style not showing on mobile device (using SquareSpace app)

I'm sure this question/issue has been asked before, but I can't seem to find an answer.

Whenever I view my site on mobile device via the SS app (specifically, iPhone or iPad), any bold font style will initially flash bold but turn to a normal style. Only once have I seen it work correctly on mobile device. Everything looks fine on computer, even when switching to the mobile layout, but just not on mobile within SS app.  I'm not using any custom loaded fonts...only the ones that come preloaded with SS font packages (Montserrat and Poppins).

If it's helpful to know....I make text bold by first highlighting the text in a text block and simply selecting B in the pop-out menu.

I believe I read online where others having this problem had to clear their cache, rebuild blocks,  and/or do some other stuff to get it to work, but I'm hoping this is a much easier/quicker fix.

Please advise, and thank you in advance!!!