Poor suction problem

In ground vinyl liner pool with Hayward pump and cartridge filter. I ran the pump all night and in the morning I noticed that the pump basket was only about 80% full of water, where normally it is completely full. I also noticed that the pool return jets had zero flow coming from them but the return jets on the steps were flowing properly. Next, I noticed that the suction port for the vacuum in the pool had no suction. All valves were open, so there should have been suction in to the filter from the vacuum port and there should have been flow back through the pool jets. I am not sure where the problem lies here....any ideas?

Turn your pump off; open the lid; put a hose in the strainer basket and fill the basket; have a helper toggle the pump ON once the basket is full. The water should almost instantly be pumped out of the basket.

If not, the problem is the pump, filter, or something else down stream of the filter.

If it is, the problem is between the pool and the pump, on the suction side, OR a leak AT the pump or AT the strainer basket lid.