Welcome to the community @NikkifromMissis
May I ask which type of Fitbit is the subject about?
I would say to kill the Fitbit app and restart the firmware update.
Depending on the tracker their could be other steps to try.
Best AnswerHave you tried updating the formware through both wifi and Bluetooth?
I had to setup the Versa, choose to ignore the wifi setup and go straight to Bluetooth for updating