Any search result I click on, while it looks like the right link when I hover the mouse over it, it gets redirected to the page to buy Icewind Dale. Bizarre. I can't lookup stats on monsters or descriptions of equipment or ...

Have you purchased a license to that book from this website?

No. Are the stats for everything in that book? It was doing it for every search term. "Fox", "Frost Druid", "Fire Bolt", "Ogre". Today things are different. A search for "Fox" today turns up zero search results which are mainly about a creature called a "fox", they're all pages which have the term "fox" on them somewhere. "Ogre" returns zero results at all. This is a very strange search engine.

The search function on this site has always been notoriously unreliable at best. However, the functionality you described in your OP is exactly the way it would always work if one didn’t have access to the specific content they wanted to see. It would display a result was available to view, but if we didn’t have permission to view it (either through purchase or content sharing), then it would redirect to the store where we could purchase that permission.