A GlobalVariable.X is scoped for a single test suite run. Test cases in a Test Suite can share the value of GlobalVariable.X. But Test Suite A and Test Suite B can not share the dynamically updated value of GlobalVariable.X. GlobalVariable is designed as such. You can not change this behavior.
If you want to pass information across multiple test suites, you should create a file and write/read info for yourself.
Test Case a1 in the Test Suite A creates a file and save the value into it; Test Case b1 in the Test Suite B reads the file and consume info in it. You can employ any format for the file. If I were you, I would employ JSON format as Groovy language supports JSON natively. Please have a look at my previous post for a sample code:
Or you can use a Excel file. See the following previous post of mine:
This post is titled “multiple test cases in a test suite can share a excel file”. But more precisely in fact “multiple test cases in multiple Test Suites can share a excel file”.
Or simply you can use the Excel keyword plugin:
https://store.katalon.com/product/34/Excel-Keywords