An example of a module that largely has a sandbox approach would be Dragonheist as far as I can remember (it's been a while). I skimmed through the module after we played but unfortunately the DM we had didn't really understand that and it just kind of fell apart. The thing is that it tells you about a treasure hunt of sorts where multiple factions are pursuing the same treasure. It lets you know different factions, what their goals are, how they are likely to react to the PCs, but that's about it. It gives you various plot hooks but that's it, there isn't really a linear path and if the PCs faff around enough a specific organization gets all the money. But our DM didn't really understand that or how to make it all work. I've heard the same complaints about Rime of the Frostmaiden.
So yes, some modules are designed to be settings, not linear adventure paths. They don't work for some people.
Actually Dragon Heist has whatever the term would be for a fake sandbox (I guess that would be a railroad?). It LOOKS like the group has choice in how it wants to Maneuver, order of approach etc but in reality the order things must happen is completely fixed.
In fact, Dragon Heist has one of the worst, most irritating examples of railroading I have ever seen in a public module:
The PCs are in search for the McGuffin. IF the PCs find it early (early bring defined by the McGuffin itself, so the DM) through smart play, luck or whatever, the McGuffin will LITERALLY erase the PCs memories of them having found it and set them back, until the McGuffin (aka DM) thinks it is the right time to be found.
I will be surprised if ANYONE here would think this is a good way to do it!