Fuel pressure issue

i put a new mechanical fuel pump on last summer and this year I swapped to a edelbrock avs 2 650cfm. Installed a jegs brand fuel pressure regulator and it worked fine for like a week. Now I’m having pressures issues. It’s set at 5.5 per edelbrock and now when warm the pressure fluctuates between the 5.5 setting drops to 3 and then back up. Causing the idle to surge.