When you create your render, check  your stuff used, that are not seen, remove that. If you use alot of textures and you can't see it hiding behind stuff, remove it. It takes alot of time. Then if you render make sure you render in bigger sizes than small, like 2100x2100, etc. I have experience with the smaller the picture, the longer it renders. The bigger the better. A glitch or something in 2.2. Just my 2 cents I figured out. Hugs