Sounds like glans stimulation versus shaft/frenulum stimulation differences. Glans is involved for me during masturbation for sure, but when it's time to shoot and orgasm, I never pull my hand over the glans, I keep my hand going up to just the bottom 1/3rd of it, with like a squeeze/tugging kind of action, and my frenulum is being pulled/squeezed too. My f is very intact, my doctor cut me the best way possible, thank GOD for that man! When I'm in my wife my glans is obviously being overstimulated and I can only pump/move so much, and while it feels good, I don't cum as hard as I can when I'm out in the open.
This is because I can keep stroking/tugging on my cock while orgasm and ejaculation is happening and I keep doing it until the pulsing is completely gone. All of my orgasms last well over 30 seconds, and on nights when my wife and I have a major fuck session and I pull out to release all over her (and the floor/surface behind her usually) those orgasms last 45 seconds to sometimes a whole minute. INTENSE AF. I don't know how my body makes it happen, but it does. My genitals were made to cum a lot and for a long time I guess!!
Maybe you guys that can't keep stimulating your cock while orgasm happens should just work on the shaft/frenulum and not the glans? If you have a frenulum left, give it a whirl! Hard to change our "cum programming" at a later age I'm sure, but maybe y'all will break through and have a good time!