I have a 2013 Chevy Impala and my transmission in overdrive has some slippage but 95% of the time it shifts perfectly has no issues. So I'm wondering if it's a mechanical or if there's some sort of other electrical issue.

Thoughts?

 

Check the trans fluid. Make sure the fluid level is correct. If it brown and smells burnt may need a rebuild.
Check for DTC and post them here