Windows Phone Games : Achievements can't be found on the Xbox app

I found different symptoms of xbox app on different platform:

Xbox app on xbox one always should total achievement as zero for all games. You can see which game you are playing, but you can't turn on achievement tracker as it always grey out.

Xbox app on windows 10 navigate to achievement page on any game, it just keeps loading. After a while the achievement tab will even disappeared.

Xbox app on android / windows 10 mobile cannot access to any achievement page, and some time

Xbox app on windows 8 / windows phone 8, & achievement page on
xbox 360 surprisingly work fine and able to show achievements correctly.

Not sure is there any way to fix all this....

My windows phone achievements are not syncing. The achievements pop in the game with the normal achievement notification, and the in game achievement menu shows that I have unlocked the achievement, but the achievements are not syncing with xbox (yes we
know that windows phone games do not show up on the xbox app and only show up on the 360 achievement menu). Please help us. There are many people on Trueachievements with this problem.

On my windows Phone it has an inbuilt Xbox live app that stores your games, allows you to update your profile and check achievements but only window phone games and Xbox 360 appear the Xbox one doesn't

@ Dakrkplayer2

yes I'm always connected to Xbox live and the internet.

@Lightspeedhero

The in game collectible tab shows I have all collectibles and no achievement for me. I can't try the companion app as it doesn't work for windows phones.

That part I understand. So why is the XBOX Games app working for the phone and not for the Windows 8.1 PC or tablet? At least they should have shut everything down across the board or shut down the ability to access XBOX achievements on the phone as well
as the Games app there and keep the Windows 8.1 version running.