Then you’ve absolutely got to approach the lab director and figure out what they are doing.
Totally agree that getting the extraction right is on them, and incomplete or even inconsistent extraction from edibles is a known issue, but it is also VERY easy to get edibles that are not homogeneous, so pitching it as “…it might be my fault…” is not unreasonable.
Testing lots of individual edibles gets expensive, but if you can demonstrate homogeneity, it’s often easier to convince folks they should give you a price break on the R&D they now have to do to get their extraction efficiency on point.
There may be information they would find useful here: Suggested methods for measuring cannabinoids in gummies and other edibles