I took a look at this in my test project in 6.10.10 and cannot reproduce the issue. When I press the enter key, I get the new data in my microflow as expected.
Can you create a test project with the bug and invite me to it? My email is my first name dot last name at Mendix.
(2) Microflow -for sending message- called when pressing the button.
(2) I added a new Action Button, which called my microflow to send messages. Afterwards, I connected the KeyboardShortcut-widget to this button, and connected it with the enter-key.
With this solution everything works like it should.
Thank you for your answer anyway!