i-STAT AQ CAP survey bias

Wondering if anyone else has experienced bias with your CAP AQ survey for the i-STAT.  On the AQ surveys from 2021, 2022, and two so far this year, my Sodium and H&H show a negative bias and my Lactate shows a positive bias. I sent this concern to Abbott and they asked if the results were passing - yes.  What transfer device are you using to fill the cartridge - 3 cc syringe, no needle.  They also asked for the lot #s of the CG4 and Chem 8 cartridges used in the most recent survey.  Their response was: "Upon review of the results and information you provided, since the results for your CAP survey are considered acceptable, there is no evidence that i-STAT 1 Analyzer or cartridges are not functioning as expected.  Acceptable ranges for the survey were generated amongst peer-to-peer testing with the group mean used to calculate the ranges. Variability of operator technique could contribute to differences in results.  At this time an investigation is not required."

We rotate analyzers and operators.  Anyone have a similar experience; thoughts?  Thank you!