There is no visible vent. Do you see one outside, on the roof, in the area of the kitchen?
Disassemble the left sink horizontal arm and the end outlet tee (the white piece below the black disposer discharge) - clean them. The end outlet tee should have a divider inside, to separate the water coming from the disposer and from the left sink. If not, replace it. I would clean the trap as well.
Assemble in reverse order. Check for operation and for leaks.
Other than that, this arrangement setup that you have should be OK, except that I like to have the disposer on the left sink.