Working pressure lower with new setup.

[Gorillastomp]

I reworked my piping maybe a month ago to increase the pump size on my system. With the new layout, i inject my CO2 directly to a diy cerges reactor type (which appears to be too small for the system, bubble evacuate to the outlet in the tank). Now when i open my needle valve to a certain point my working pressure gauge drop down to 20 psi, with the old system it was steady at 40 psi.

Is this because the regulator could be clogged or the overall resistance of the system is lower so the co2 flow better into the system ?