It sounds like you've diagnosed the source of the issue quite well! We know the general source is the problem machine, and we also know the problem isn't with the commands being given, as it happens with any cell, regardless of its content. Additionally, since it works on the Mac without issue, we can rule out problems with the Mathematica software itself.

Have you tried checking the system logs on the remote machine for any error messages or warnings that might give more insight into why the Math Kernel process is quitting? It might also be helpful to ensure that the problem machine is set up properly to handle the remote connection. If the issue persists, reaching out to Wolfram Support could provide further assistance.

Yes, Mathematica works perfectly locally on each machine. In fact, this is an issue with this particular local Windows machine : i have another local computer, a Mac, which can use the remote Linux machine without any problem...

It happens with any cell, no matter its content it seems...