Issues with Advection Term and XDMF Export

[remidm]

Hi @Andrea do you mind sharing at least a screenshot of what you see? I can’t reproduce your issue since I don’t have your mesh.

It will be easier for the community to help you if you provide a Minimum Working Example (MWE) instead of the full application.

@remidm

• Post a “minimum working code example” (MWE) to illustrate the problem:
  A MWE is the simplest piece of code that reproduces or explains the problem you have.
  It must be possible to take the MWE, paste it into a file and run it, without any extra modifications. Good MWEs can be as little as 10 lines of code. If you can remove a line of code from your MWE and still show your problem, then you don’t have an MWE!