Random text rendering

I have no idea where this should be directed; If someone can point me to the right place I’ll go there. Problem: I have begun landing on websites that render text in a garbled form: In the simplest case, “Hello World” (generated by the opening example in W3Schools’ tutorial on Node.js) looks like the attached image. Other browsers (Chrome, Safari) have no problem. Viewing page source shows “Hello World!”. Please don’t make me leave Firefox!!

Screenshot 2023-10-18 at 4.09.17 PM|350x138