Globals are local to the clients machine.
Changing a global as a client will changes the field only on their local copy.
The global on the server is not changed.
One technique - use a 1 record table to hold all the fields that are considered "project globals". Since the data is held in a record it will be able to be modified by clients and reflected on all users local copies.
You will need a relationship between the project table and your other tables.
I'm sure you will get some other techniques from other users.