Immersion Silver - surface problems (need experienced help)

We have had some test results come back after we were getting poor wetting in our joints, we requested an EDS on our joints from our PCB supplier. They have provided the results and said that it was their fault and will replace.

What I want to know is what elements should be present in an immersion silver pad? - Before soldering.

Our results show: C @1.42%, Cu @ 3.39%, Ag @ 95.1%

Our supplier has said that the "high C element" is the reason for failure. I'm also wondering what high carbon does to a solder joint?

Any thoughts would be much appreciated and any information on Imm.S plate results.

Kind Regards Adam

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