>>798716How deep is that pot? At least for my regular basil, it quickly grew its root very deep
Pic related my December seedling shortly before I had planted it out in the garden in late April, by that time the roots had already come out of the drain hole and were going in circles massively at the bottom, was surprised to see that when whacking away the pot, such a puny herb has so much root growth. Maybe yours' roots are also already concentrated at the bottom where it may be too wet?