Heat conduction in solids - temperature dependent heat transfer coefficient

Hi,

I would like to solve a simple heat conduction in solids problem with a temperature-dependent heat transfer coefficient at one of the boundaries

h(T) = 1000*(300/T)^1.3

However, the result computed by Comsol is different than I would expect from analytical techniques and an equivalent Comsol model with a solid layer of very low thermal conductivity.

Are there any issues I should be aware of when using temperature-dependent heat transfer coefficients?

Thanks,
Kevin