Steam Achievements already completed but shown as unlocked and others shown as locked and unlocked.

CARMARA#3378

I do have several Steam Achievements that I already "unlocked" BUT the problem is that no matter what I do these achievements keep showing like "locked" or not achieved yet. What is totally weird is the fact that even some of those achievements were reported at the end of the game as "unlocked" or "achieved", but later on the achievement is shown as still "unlocked" and the worst part is that I did try to re-create the conditions in order to earn again the achievement but once I arrive at the end of the game (while playing another game) I ended being frustrated because this time the achievement is not reported as unlocked anymore. that is the case for the following achievements:

1.- The More Things Change ...Change your state religion and convert 50% of your empire's population to it.

2.- It's a start… Sink 10 enemy ships during naval battles.

3.- Watery Graves... Sink 100 enemy ships during naval battles.

4.- Tactical Genius... Use 3 abilities during a single campaign battle.

5.- Show No Mercy!... Kill at least 1,000 enemy troops in a single campaign battle.

6.- Caesar Reborn... Complete the Grand Campaign on legendary difficulty by fighting and winning every battle.

And what is even more weird is that the following achievement appears at the same time as "locked" and "unlocked" and I don't understand how is that even possible,

7.- Veni, Vedi, Vici! ... Complete the Grand Campaign by fighting and winning every battle.

It is worth mentioning that I already have 67 out of 118 achievements for Total War Attila already earned or unlocked and I want my other 7 achievements to be reported as earned too...

Can anybody supply a solution for this?