Fitbit blaze not syncing steps in challenge properly

[Shev90]

I have a fitbit blaze and it says on my Fitbit screen that I've done 12,659 steps, it also says the sand on my home screen on my Fitbit app 

I'm in a workweek hustle challenge and it says I've done 11,648 

I'm in this sort of challenge every week and ive noticed it takes at least 1k steps off me each day and I'm not sure why or how to fix it

thank you 

[SteveH]

One reason this can happen is if some of your steps were not directly tracked by your fitbit. Any steps from a manually logged activity or from a 3rd party app do not count towards challenges. Could this be the problem here?

[Shev90]

Hello

the only other 'tracker' I have is my phone,

i also have Strava but I'm not sure that records steps 

so I'm unsure if that's why

[Rich_Laue]

Another reason is if the challenge was started in another timezone.

Next week join a challenge and start one of your own inviting the same people.