Solution diverges at high Reynolds numbers and fine grid in COMSOL
 

Hi, I'm using COMSOL to simulate heat transfer of a flow over a series of cylinders.
When I use Reynolds numbers bigger than 100, the solution only converges with normal mesh and it diverges with finer meshes!

It diverges with following grid at Re=200 and converges with Re=100!
https://i.imgur.com/dgn7vFm.jpg

And It will be converged with this grid:
https://i.imgur.com/rLYGrgY.jpg

And it makes me unable to check mesh dependency.

Is there any reason?