I have played through Legendary difficulty twice on different profiles and the 3 complete the game on such and such difficulty achievements won't unlock. I of course had crashes to desktop and disconnects. whenever that happened I always restarted the level I was on.
So two playthroughs I am fed up. The internet is no help, so I try that gray area cheating where you rename the level files. I first do it on a dummy tag on another computer. All the achievements unlock fine.
I try it with my main tag on both the original computer and 2nd computer. Nothing unlocks.
I try different difficulties. Nothing unlocks.
I try different profiles. nothing unlocks.
I try it with a 2nd dummy tag on the original computer. achievements unlock.
I get a 3rd computer that my tag had not been on. did the level thing. nothing unlocks.
I tried everything again on the 3rd computer. nothing unlocks.
My brother plays through legendary difficulty legit on the 3rd computer on his tag. achievements unlock.
So my guess is that either something is flagged in my tag or on the live servers where the checkpoints are "kept". Any ideas, suggestions, solutions, help? please.