Infill showing through the model

Try reducing the infill wall overlap

It is defaulted at 15% so try 5% to -5%

Also if your wall line count is at 2 you might try 3 walls

As well you could try and change your infill pattern, grid is a tricky one to dial in

I use Gyroid infill more often than not but if strength isn’t really required the Lines pattern works well in many cases

To reduce time you could also select infill combination