Can your thyroid be normal on a test yet still cause symptoms?
The studies provided concern thyroid abnormalities in cancer patients and medication choice, not symptoms in the presence of a normal thyroid test. Your question cannot be answered with these sources; discuss this with your general practitioner or internist.
The available studies do not address the situation in which someone has symptoms but a normal TSH value. The claims examined concern thyroid abnormalities in cancer patients receiving immunotherapy, and a comparison of generic versus brand-name thyroid hormone. That is a different question from the one you are asking.
On the basis of the sources provided, I therefore cannot confirm or deny that a 'normal' TSH value can still be accompanied by thyroid symptoms. That question, which concerns things such as symptoms with a borderline TSH, free thyroid hormones, conversion problems or tissue needs, has not been investigated in the studies provided.
What the sources do show is that in cancer patients receiving immunotherapy, the timeline of thyroid problems matters. A pre-existing abnormal TSH before the start of treatment is associated with shorter survival. A thyroid problem that develops as a result of the therapy is, by contrast, associated with longer survival. These are associations, not proof of cause and effect, and they apply to a specific patient population. Furthermore, research indicates that generic and brand-name thyroid hormone are equally effective at normalising TSH values.
None of the claims provided concern the relationship between normal TSH values and the existence of thyroid symptoms in people without cancer or immunotherapy. The question cannot be answered on the basis of the available sources.