Cats will always eat the food if it’s not in a feeding station, especially when they’ve had it before, they make it part of their nightly route once they know where it is. Either try the brick method of blocking the entrance a little or put an entrance tunnel in and I’m sure it will stop them. I’ve got entrance tunnels on both of mine which stops the cats but I would also point out it sometimes takes a bit of investigating for hogs to work out how to get in. Our resident is now totally used to it and the other station out the front has also been used but I have seen some hogs sniff around for a bit because they can obviously smell the food then wander off because they can’t work it out.
I got some pipe which is 125 mm wide and pretty much perfect for the job here:
https://www.toolstation.com/125-round-pipe/p89189
It’s 350 mm long so you could shorten it a bit if you want
