I have been able to duplicate this issue as posted in the Support forum here:
https://wordpress.org/support/topic/elementor-does-not-save-changes-elementor-no-guarda-cambios-se-queda-en-cargando-2/

When Authors and Contributors attempt to save, the save continues and the green progress bar does not go all the way.
Note that neither of these roles have been excluded in Elementor > Settings.

Rolling back to 1.7.12 and both roles are able to save usual.

Cheers!
Lyle