Had the same issues with an Edelbrock carb, I’m sure you know why.
Added a return T’d right at the carb inlet and an inline restrictor orifice for the return that keeps the main line pressure around 6 pounds.
When choosing the restrictor I used a gauge to show the main line pressure.
No return regulator needed.
Running the same system with the Holley thats been on there for a few years now.