Strange, I can log in through my laptop, but impossible do it through my particle app on my tablet… of course using the same informations.
Have you ever experienced that?
They should be the same. Can you check if the email address is the same?
That’s why I’m driving crazy : I use exactly the same email and password that I use for logging in this forum! And it used to work as I already claimed my photon.
It should be the account for build.particle.io and the forum 
Your forum credentials don’t (neccessarily) have anything to do with your Build account.
Even if you intended to have the same credentials on both sides typos could have happened and the browser’s password vault hides that fact from you.
Log out of Build, try logging back in and check if your devices are present there.
I have the same problem. I reset my account via the website but cannot log on using the app. keeps telling me that my user credentials are invalid. Uninstalled and reinstalled app - no change. Any suggestions?