I always dig deep into achievement which neither work nor do not work. I finally managed to get stable achievement progress.

Let me try to explain the way i assume makes achievements reset:

When a player starts OT:DC, achievement progress is loaded from steam into the game's memory. When player clicks continue or new game, achievements from that memory are "copied" into current game. If you finish a game, let's say that your achievement counter for completing 5 games increased from 2 to 3. If you exit the game BEFORE starting new game, then start the game, fresh progress will load into the game. BUT if you start new game before exiting, it will load old progress from memory mentioned before. It will then upload it to steam, should any of the counters change.
It is pretty strange that game remembers old achievement state.

Now, i had complete achievement progress reset when i tried endless mode. I cannot say why, but my counters turned to much earlier state than they were when i started the game. This means that for those achievement to work properly, it is much safer to play campaign rather than endless. Although it may be just because i did not exited for a long time, but i do not think that i visited only a single graveyard in previous game session which i ended myself without starting any games after getting to menu.

In short: for achievement progress to be recorded properly, exit the game each time you end up in menu (when you finish the game or when you manually do it). Do not start new game or continue old one before you reenter the game. Also, play campaign for said achievement, as endless seem to be screwing them up no matter what.