What are you trying to 'snap'?

This is a feature I've never used, but I just tried it, and it's working for me.

I've tried all kinds of symbols. Brackets, systems etc. Nothing 'snaps' to guide. I've got everything clicked in the 'items to snap' box. 

I assume it is supposed to be like the 'snap to' that occurs in adobe software?

P

… The feature only works on the first page where the actual guide arrows appear in the ruler, not on the subsequent pages where the guide lines appear with no arrows in the ruler …

Patrick Farrell,

Because of your word ‘pages’ I suppose that you are in Page View - right?

Take a look in the View menu.

What is your viewing style?

I suspect that your viewing style is connected to the problem.

My snap to guide does not work at all. I was under the illusion it was working earlier but I was wrong (so I've deleted the relevant posts to keep things clear). 

Also there is nothing about the view affecting snap anywhere in the relevant literature.

https://usermanuals.finalemusic.com/Finale2014Win/Content/Finale/GUIDEITEMSDLG.htm

I like to view my music in page view - book style: row

Maybe I should make a youtube to demo the issue?