It is normal for the coolant to raise in the bottle when hot, and hoses would go harder, but wouldn't expect to be hard the following day!
If you are running the black coolant cap they were prone to failure on the pressure relief system in the cap. If you are running the black cap, then update to the later blue one from VW with a much improved design.
It does sound like there is a possible air lock in the system and the coolant is not circulating (if all is well you should see it re-circulating into the coolant bottle from the smaller hose).
Try running the