Generally I'd have to see what it's doing, but as a USER I know that these "one or two question per page" setups often just piss me off. Generally I prefer when there's a bunch of options to have them all on one page.
What tabs CSS demo are you using? Generally if I were to implement such a thing I'd have it be hash link driven, in which case forward/back buttons would just be anchors href="#section1" and href="#section3" (if on #section2). See my x86 reference which is actually one giant page of markup despite looking like a SPA.
For example if you look at the page for the MUL instruction:https://x86.cutcodedown.com/#opcode_MUL
You can see it has forward and back buttons to MOVZX and NEG respectively. In the code MOVZX is:
And any link to that section would be:
That said, making it a single page with tabs is bad UX, and would make section validation a pain in the ass. I'd either make it one tall form so client-side validation is easier to handle. Playing around with fancy tricks is just going to harm the experience, not help it.
I don't know about anyone else, but when I'm 8 or 9 pages deep in some goofy form trickery, I have the habit of saying "screw this" and going to use something else.