Nabu app doesn't connect to the razer account

Hello, I own a nabu watch (forged edition) which has troubles (as seen in other threads, like crashing when a phone call comes...) since my android phone did the OS upgrade to version 9. The last trouble is that I'm now unable to connect to the app ! When I enter my email and password, I got a message which tell me that there's no user data found... This is strange, because the account is valid : I can write this message in this forum and my other materials do the connection to my account... I guess there's a kind of compatibility software problem between the android OS and the app, but, maybe it's something, else, so any clues or ideas ? Thanks in advance !