Hi Veggie. I am not able to test it prior to new flex line. The whole plumbing system is DOA, due to PO using white water hose w/clamps to make repairs to the copper lines.
I may hook up to the toilet with a sharkbite, to test toilet and valve, then replace copper and flex line with new flex line to pex. That way if the valve is bad, I can go to your posts and fix it.