Help: under gassed or over gassed

[Dt219]

I did try it on my other lowers and it was the same result but they had heavier buffers in them including one rifle length which is a good bit heavier. I went with a lighter standard carbine buffer and it cycled all my reloads I thought maybe it was under gassed also, I have 1 semi auto bolt carrier I swapped it out thinking it will lighten it up even more hoping it would cycle and lock back the factory 90gr noslers and it did. Fired 1 locked back, fired 1 locked back then I put 2 in the magazine it cycled the first and locked back on the second. So I’m pretty sure it’s under gassed, I do not want to open the port in the barrel so I ordered a reduced power spring from sprinco to try or I might just leave it alone. Do you think it was under gassed now also ?