Ok, add a few squeezes .
Try jelqing with the soft web skin between forefinger and thumb running over the middle dorsal part of the penis, and have your fingers press on the sides (as opposed to the cs).
Each jelq should take longer imo, have a look at this tntjockey - New Jelq City!.
You could try to do 5 mn of jelqing x 3 with squeezes in between sets, or kegel with an overhand grip half tightened at the base (tighten it after the kegel so blood successfully inflates the penis), squeeze for a while (feel the bulge of blood pushing above your grip against it), and then proceed to a very slow jelq, then repeat.
As for the pump, it’s a bit annoying to not be able to monitor pressure. Is there any specific reason you are using a pump?
Do you warm up thoroughly before the session? Quite a few say it could help one gain.
To summarize my disorganized post I will say you need to ramp up the intensity in terms of manual work.