Clopesed radiator hose

Sounds like your thermostat is not opening or you have air in your cooling system after the flush. Tstat is not likely since you did not open the housing or replace it. Having the hose collapse will not typically ruin it so try getting the air out of the system and see if the problem goes away. To do this, fill your system, leave the radiator cap off or loose, and run the car for a few minutes to let the Tstat open. After that turn it off and let it sit with the cap off. then recheck the coolant level and close the cap. Now go test run the car to see if the hose no longer collapses.