In the latest Bedrock versions (1.4.x), Windows 10 clients don't submit all the form data back to the server in the response - applies to text fields only that are unmodified from the original placeholder text.
Here is an example of what clients submit back to the server in ModalFormResponsePacket:
[true,true,10,2,49,false,""] - android/ios
[true,true,1,2,49,false,] - windows 10
The order is: toggle switch, toggle switch, dropdown, dropdown, dropdown, toggle switch, text field
All clients should be submitting "" back if the text field was left unmodified. The data that Windows 10 clients respond with causes the JSON decode process on the server side to mess up and the submitted data not being handled properly.
Cleaning up old tickets: This ticket has not been updated recently (~1 year+) so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines.
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