Not enough to water to spin spray arms

Our dishwasher wasn’t cleaning properly so I recently cleaned the filters, replaced all the spray arms and the water inlet valve because it wasn’t getting enough water. That seemed to fix the problem for a few weeks until the other day we noticed it wasn’t cleaning well again. I discovered that only the bottom spray arm seems to be spinning. I took it off and it has two decent size holes that have been caused by being burned by the heating element. Do you think this could cause the problem of not getting enough water to the other spray arms? What would cause this to happen?

If you don’t think that may be the problem. From my research, it seems like I may either have a problem with motor or the impeller. However, The motor and pump are both working and it drains properly. I would appreciate any assistance you may be able to offer. Also if you have a service manual for my model that would be helpful. Thank you