Shark Bite plumbing fittings can leak if you do not install them properly.
To ensure a Shark Bite fitting does not leak you need to cut the pipes straight and ensure there's no burs or debris on the pipe or inside the Shark Bite Fitting.
When you have a good clean straight cut pipe that has no burs on it or debris and you push the Shark Bite coupling or fitting onto the pipe firmly then it should not leak.
You must install the Shark Bite fittings properly or they can leak which happened to myself before.
That was my fault though because I didn't install them properly or clean the pipes of the burs.
Once I cleaned the pipes of the burs and debris and made sure the pipe ends were cut straight and I pushed the shark bite fitting on firmly then I had no leaks from shark bite fittings.
They are good fittings as long as you install them properly.