Not odd at all. Hypo patients frequently find that their serum levels of Free T4 and Free T3 do not start to rise until after their TSH becomes suppressed below range. That is because serum levels are comprised of endogenous thyroid hormone from the thyroid gland as well as from exogenous sources (thyroid med). As med is increased, TSH goes down and the thyroid gland produces less. The net effect can be basically nothing until your body is totally dependent on thyroid med. For example, my TSH has been .05 or less for probably 35 years in order to get my serum thyroid levels high enough.
This is a link to a scientific study showing that "Suppression of TSH by thyroid replacement to levels below 0.1 mU/L predicted euthyroidism in 92% of cases, compared to 34% when TSH was above 1 mU/L (p < 0.0001). In conclusion, in central hypothyroidism baseline TSH is usually within normal values, and is further suppressed by exogenous thyroid hormone as in primary hypothyroidism, but to lower levels. Thus, insufficient replacement may be reflected by inappropriately elevated TSH levels, and may lead to dosage increment."
So your next steps should be to continue to gradually raise your med in order to get your Free T4 to the middle of its range, and your Free T3 into the upper part of its range, as necessary to relieve hypo symptoms. I say that because Free T3 has been shown to correlate best with hypo symptoms, while Free T4 and TSH did not correlate.
In addition since hypo patients are frequently too low in the rnages for Vitamin D, B12 and ferritin, you should make sure to get those tested as well. D should be about 55-60, B12 in the upper end of its range, and ferritin about 60 minimum for ladies.