slow rendering and frozen frames in unity 2019.4.16f

We know nothing about your game, what the 3D environment looks like, what the players look like, what the UI looks like, how it behaves, what hardware it runs at "50 to 60 fps" on. We know nothing about what you've made, you shouldn't expect us to, and to a large extent, it's also not really important for us to know. Too much information can be overwhel$$anonymous$$g, but too little and there's no reasonable way to offer guidance without simply guessing.

With how little information we *DO* have, all we can really offer as suggestions is to look at the profiler and see where the most time is taken during your frames, especially for the times where you have the greatest framerate hits/hiccups. This is really just a time to take a look at it and get familiar with what it's showing you.