Problem with mesh cells

Good afternoon,

After starting transient solver, I got this error "Port 1 is inhomogeneously filled within the first 3 mesh cells.". I've found some solutions proposed here in forum: increasing the number of mesh cells or adjusting the size of my port. But this leads me to a very long simulation time and sometimes my structure is filled by PEC cells.

Note that I'm trying to simulate a stack microstrip antenna in LTE1 band in a cylindrical surface.

I'm sending my file attached.

I can't think in other solutions. I hope someone with more experience can help me in this problem. I would be truly grateful.

Thanks.