If it works fine on another ISP then it means your current ISP is a bunch of jerks. They have for whatever reason set the connection to disconnect even if you are using it. Very strange since this would also impact people who work from home and would have stuff like video meeting interrupted.
It could be as simple as they do not make enough profit off customers like you. They want the customers who pay for the service and then not use it much so they make the service not run well for people who use it more hoping they will cancel.
Unfortunately unless the contract with them states they can't disconnect you every 2 hours they can do what ever they want.
Best option is to find a better ISP and make sure you find review places and post the fact that they disconnect every 2 hours. All depends on the costs if your current ISP is much cheaper than other ISP many people will tolerate the 2 hour disconnect to pay less money
It could be as simple as they do not make enough profit off customers like you. They want the customers who pay for the service and then not use it much so they make the service not run well for people who use it more hoping they will cancel.
Unfortunately unless the contract with them states they can't disconnect you every 2 hours they can do what ever they want.
Best option is to find a better ISP and make sure you find review places and post the fact that they disconnect every 2 hours. All depends on the costs if your current ISP is much cheaper than other ISP many people will tolerate the 2 hour disconnect to pay less money