If it is the tank not sitting on its stand properly i would try to keep it on an even surface because if it's not the pressure may cause your tank to crack in the future.
(say for example theres a chair thats on an unleveled surface with weight on it, with the weight only being distributed between 3 legs instead of 4 and this chair has weight on it 24/7 for months+ it will eventually break)
If it was sitting on the stand properly and was just on a slope as is i would still move it there's no harm in being overly safe.