My gears of war 2 isn't unlocking accivments

I'm playing gears 2 and it's not unlocking accivments but on my console it's showing that I have done it what can I do if anybody can help contact me at *** Die E-Mail-Adresse wurde aus Datenschutzgründen entfernt. *** my gamertag is i really want to do it on insane but cant if it won't unlock
I have been on to Microsoft and all they keep doing is putting me on to different people an troubleshooting I have uninstalled an reinstalled again still nothing I did the active reload accivment an the train the rookie to see if it worked but still not unlocking
but on my account it shows I did it on hard-core on my Xbox one but all the accivments have just gone an there not unlocking when I go to do the accivments again need help please

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I thought i had a problem with a game to find out all my 360 accivments have been reset

I just come back to my Xbox from ps4 I'm on the xbox 360 but signed my account in to see all my Xbox 360 game accivments have been reset first noticed when I started to do gears of war 2 again an it said I had no accivments for it but on my console it clearly
shows I done the game on hard-core so 2 weeks on to Microsoft an Xbox live and unreal gaming support I notice that it's not just gears it's every singe Xbox 360 game I have ever done and my gamerscore was only about 2k when I got back to it when b4 I went
to ps4 it was 18k+ can anybody help and tell me why they have reset my gamerscore now when I do the games again it's not unlocking accivments ??? Can it be that when I sold my last Xbox I have the account with it because her child didn't have any games and
I didn't think I'd come back to Xbox or is it if she factory reset the Xbox I shouldn't think that would affect my account and my gamerscore accivments etc somebody please help email me at *** Die E-Mail-Adresse wurde aus Datenschutzgründen entfernt. ***

 

Achievements not unlocking for Backwards Compatibility Games

For Borderlands, Gears of War 2, and now Saints Row IV, no achievements are unlocking. I have beaten Gears of War 2, achievements stopped unlocking after Chapter 2.

Progression achievements, such as Kill 100,000 enemies, are reset to 0 each time I log in.

Customer Support said to post here.

Ideas?