I live at Ground Zero for black bears in the Ozarks.
We have a Conex that we use for storing bear bait.
A year or three back we had a bear come up and tear the door off of a Conex container, with two dogs harassing it, and a chain/padlock holding it closed. He just dumped out 55 gallon drums, ate his fill, and left.
So far nothing that we have found as a non-lethal option has deterred them if they get it in their mind that they want your feeder, trash, or whatever.
Electric fence? Tried and failed.
Noise or visual alerts? Don't bother.
Less lethal shotgun ammo? Good luck but it was useless to us.
I had occasion to spend summers in the back side of beyond in western state for 5 or so years caretaking remote Wilderness Areas for the USFS. Once the local game wardens found out that I guide bear hunts in my home state I got "appointed" as the problem bear guy for our area since the GW's were often 2-4 hours away when a call came in whereas I lived on site or close to it. We tried rubber bullets, air horns, taser rounds, and sand bag rounds all without much result. We finally got to the point where I was authorized to use lethal force on the problem bears IF I could do so out of the public eye.
I suspect that your problems are going to mirror mine in that you can NOT discourage a determined bear, especially if he got a food reward for his bad behavior.
I'm sorry to say that you're options are to remove feeders, kill the bear, or hunt somewhere else.