In the current version of ROBLOX, TextBox objects under certain condtitions will have their Focused event fire twice when only focusing on the box once. This happens when a keyboard input detected using the InputBegan event of UserInputService calls the CaptureFocus method on the text box. It correctly fires the Focused event when the method is called however it also fires the event when the key is released for no visible reason. This has happened in all tests.
This place contains a textbox with scripts already set up to print to console when the text box is focused, unfocused and responds to use of the E key to focus the text box: https://www.roblox.com/games/1225683524/TextBox-Test
Expected output:
About to use CaptureFocus()
Focus
Just used CaptureFocus()
Actual output:
About to use CaptureFocus()
Focus
Just used CaptureFocus()
Focus