Hitachi 40U installing thumb issue

Good day everyone, I have a 2004 Hitachi 40U. I recently added a EFI hydraulic thumb to it. As it was not set up for a thumb I had to make up mounting ears for the cylinder and plumb in all the high-pressure lines. There was a spare section in the manifold so made connecting easy. I also purchased and installed the 2 new relief valves. Once that was all complete I put in all the low-pressure pilot lines. I Teed into one of the main low-pressure lines and connected it to the P1 port on the block under the 12v DC closed centre D03 control valve. I teed into a return line back to the hydraulic tank and connected it to the T1. A and B lines went down to the manifold to control the high-pressure flow for the thumb cylinder. When I push the open button on the joystick the thumb will open when I release the button the thumb does not stop but slows down but still continues to move. It also does this when I push the close button. I thought it was a faulty closed centre valve and changed it out to another but it still did it. I tried teeing into a bunch of different low-pressure lines to see if that would help; unfortunately, they all did the same thing. I tried disconnecting the return and just running it into a bucket thinking maybe it was getting some back pressure as it was teed into another return, resulting in not letting the valve fully return to center; but changed nothing. I unplugged the + and - wires to the solenoids and tried the manual buttons to see if there may have been something to do with the wiring but had the same results. Picture attached of the high-pressure manifold with high-pressure lines coming into the top and the low-pressure pilot lines coming in on either end. You can see the new relief valves and the shiny new low-pressure fittings Does anyone have any thoughts? Thanks