Hi,
using global variables with the same name as local variables is a bad idea, it will bug, hopefullty this will be addressed in the next release.
as far loosing variables, I just had the case this morning with someone sharing a project with an issue, and I lost all variables ( they were referenced in the action, but missing in the variable listing), reimporting the whole project did fix this issue. Can you try this on your end?
Bye,
Jean