Odd, I will see if I can reproduce that with one of my devices. In the meantime, you can navigate to the Devices list for your project and follow the steps in this screenshot to try the update a different way.
Ah, I see what you mean @gauteh. That UI on the Firmware view for a device once an update is completed should remove the “Stop update” and “Retry” buttons and show the “Update” button I mentioned above. I’ll report this to the team. In the meantime, the approach in my last reply should get you unblocked.