NADCAP mtl PTP requirements

We are an embedded chemical analysis lab working mostly on Ni base alloys

13.2 Proficiency Testing
13.2.1 Procedures ensure participation in Proficiency Testing Program(s)
13.2.2 The laboratory used a Proficiency Testing provider in accordance with AC7101/1 Appendix C. (we use the Element spin off ptp.com which everyone accepts and also since we are based in China we join the PTP run by NCS who are a bit like a Chinese cross between EAG and NIST)
13.2.3 The participation of the laboratory in Proficiency Testing Program(s) is documented.
13.2.4 Participation in the Proficiency Testing meets the frequency requirements for all test codes held by the laboratory (see Table 1 of AC7101/1 Appendix B). (for our methods every 2 years)

Here is the important bit from appendix C:
Process A (mandated by Airbus, MTU, Safran, Airbus Helicopter, Rolls Royce, Bombardier)
Carry out PTP using a recognized PTP provider as listed in Table C.2. or as updated on eAuditNet
From table C2
PTP
Collaborative Testing Services, Inc. (CTS)
Analytical Reference Materials International, Inc. (ARMI) (LGC STANDARDS)
Rocky Mountain Reference Materials, LLC
Process B (Boeing, Eaton, Honeywell, Spirit, Textron Aviation, Pratt and Whitney)
Any PTP program is OK, so long as rules laid down in Appendix E are followed.

As of now I have the following combination of PTP results:

2021 ptp.com covers XRF (2 fail results), OES (1 fail result), C/S and O/N (all of our methods)
NCS covers XRF, OES, C/S all pass (O/N method not covered)
2022 ptp.com covers XRF, OES, C/S (O/N method not covered)
NCS covers XRF, OES, C/S all pass (O/N method not covered)

We have a central quality function which covers several labs (mechs, metallography, another chem lab etc) and they ae saying that we do not meet the requirements because we don't have a single "clean sheet" report that covers all of our test methods. And they want me to search around for another PTP kit to cover all methods (and to pass all elements) before the next NADCAP audit some time in the first half of next year. I got this in an email: "Ｉｎ accordance with Nadcap audit criteria AC7101/1 Rev.G△2 mandatory requirements，proficiency testing frequency must meet Every 2 years ａｎｄ the results are“Passed”.NADCAP External audit is expected ｉｎ the first half of next year，however, there is no satisfactory report on the French PTP master alloy project which we have participated so far."

I don't see any such requirement:
1. Our customers do not include Airbus, MTU, Safran, Airbus Helicopter, Rolls Royce, Bombardier so we don't have to use ptp.com
2. all methods have been assessed and have had passing results in the past two years on ptp.com and NCS
3. I do not see a requirement that all elements of all methods have to pass. It reads to me that participation is mandatory (and investigation and improvement is at least implied as part of the participation) but that as long as RCA and corrective actions are made and verified by re-running the sample failures are not the end of the world.

I just looked back at one of the ptp reports and 50 % of the labs have at least one red result so it seems fairly normal that it should occur and there should be pragmatic process of dealing with it.

I'd like to know what others think or have experienced.

Thank you