You could have something clogging the baffle tee, if the other bowl is draining fine.
When a disposer gets old, it starts chopping things in larger pieces, which can become a problem. I change mine every eight years.
Have you refilled your Rinse-Aid for the dishwasher?
A slow draining disposer can back up into the dishwasher if there is no air-gap; if the dishwasher drains to the disposer.