Katya has pointed out that the sides don't brown as much as the top if the dough does not see as much open oven. When a pot is too small the dough is less exposed to the oven air and it may hit the top of the lid.
Janes stuck to the lid when she removed it.
Ejo's also hit the roof, making for a nice positive of the inside volume of the pot.
However, my understanding is that the bread should have that hot air above to fully grow and crust nicely.
So I ask you to take a minute to send me three dimensions.
Lid diameter, height at the lid seat, and with the lid on. Do not include the handles.