Are you importing the module inside the forms you are both setting and referencing the variable from?
Example, create a client side module called “my_globals”, then :
# Form1
import my_globals
...
my_globals.abc = "hello"
# Form2
import my_globals
...
print(my_globals.abc)
This will print “hello” from form 2, assuming you run form 1 first to set the variable.