Not a big issue, but it doesn't let me finish my potion factory.
Minecarts with hoppers won't suck items from breweries, which they are supposed to do normally.
They can suck items from anything else, just not breweries.
Figured it out!
you need to add the flag "interact" to your region, set to allow. Use this command: /rg flag bulldog's_island interact allow
Note: This will allow others to use doors/levers/buttons, able to ride animals and minecarts, and able to open chests (but not chests that are locked with LWC). If this is a concern, we can set up a region inside your region just for your potion machine and set an interact flag on that.
Thank you amy, I did take a look at the region commands before I posted this, but since nothing mentioned breweries, I assumed it wasn't a region error.
Just for reference, it might benefit others by adding that to the command tutorial post.
Edit: It says I don't have permission to that command, but I can edit other flags, just not the interact one. I did make this region, and I am listed as owner.
Also, when I type the command to get a list of flags, interact doesn't come up as one I can do. There was one called use, which I enabled, but it still didn't work with the hopper. Any idea why I can't use the interact flag?