|If these are indeed "hubs" and not "switches" then what you describe sounds like a "broadcast storm".|
I would replace both of the units if they are indeed hubs. Hubs are antiquated and outdated and a switch would prevent a broadcast storm.
From the sounds of it, your one device is definitely having hardware issues and needs replacing no matter if it's a hub or switch.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.