I'm not sure it does use the amm as feedback, just the feedback sensor in the actual valve. I would expect to see a substantial drop in the amm when the valve is fully actuated.

Can you remove the egr to inlet pipe and confirm exhaust gases are flowing when activated?

Can you see live data when egr activated, does the amm voltage drop and can you confirm ecu is seeing egr feedback voltage?

Just a couple of points to check, looks like the ecu is not seeing the feedback