I think I would have more confidence in the Quest test results. I doubt hospitals even run FT3 tests very oftenr, so that is a reason to be skeptical. As always, more important is symptoms. How are you feeling at present? If you have no hypo symptoms, why worry about the test results? If you feel well, just try to maintain your levels. I do suggest that you supplement B12 to get it to the upper part of its range. Also, have you been tested for ferritin?
Lab results can vary over time. How far apart were the tests? Also, lab results and their associated ranges can vary from lab to lab. In this case I would compare results as a percentage of the range. For your old results the FT3 was at 90% and FT4 at 40% of their ranges. For the new results, FT3 was 42% and FT4 67%.
Without more info it is not obvious why the percentages changed like that. So it would be interesting to know if you are on thyroid mediation. If so, what type and dosage change between tests, if any. Also, most important to any diagnosis is an evaluation for symptoms typical of hypothyroidism.. What symptoms, if any, do you have?
Before further discussion, I should have asked if you delay your morning thyroid med dose until after the blood draw? The reason I ask is that it affects the results.