Chest completion not working?

I have been looking over & counting how many chest I have found recently trying to discover everything. So far so good but I came across the Necropolis, it says 16/18 chest collected. I have counted countless times from the map HUD & I have all 18! What is going on? Could be happening to different locations as well in the game like treviso. Since there is a location with a chest I have been waiting to get to since the start of the game & I am almost completed the game & have yet to get that chest. Honestly Great game but so buggy & confusing. Please help devs. I’ve been playing dragon age for years. Anyone else come across this as well?