I retested your iCloud link. When I login to icloud.com my password works but when I tried to login to Find Devices - Apple iCloud without using the iPhone it is complaining about my password. This have never been an issue, so a bit strange. So I had to create a new password and then I tried the Find My app again. Now I am able to login and find my devices.
I suspect that apple have som kind of security in place here that is not warning us about the password issue and that they force a reset. This have never happens before, It might come from me Using Find my, but I’ll keep on using it and if it happens again I’ll write it here.
Now that works! I tried the appleID from my work account and then i see the devices. I will change my password from the original account and then try again
Edit: after changing my password, it still doesn’t work… i really don’t know what causes this problem even if i try my wife’s appleID it doesn’t work
I now use it in a different way. I also use Homeassistant combined with Homey and now i have the result i wanted and see all the phones in my family. Many thanks for your effort. Maybe i’ll will use your app in the future.
Hi Martijn. I found the problem which helped for me. I could’t let it go ;). When i enter my credentials manually instead of copying my appleID and pw, i’m able to find the devices. I have checked this with 3 different appleID’s from my wife, daughter and myself. And now i could add all the devices by entering the credentials all manually and also didn’t use Uppercase letters.
TEST: 
TIP:
even if i try my wife’s appleID it doesn’t work
