Missing objects

Hello guys!

First of, I’m a total noob of creating games and I’m about to create my first one.

I think my unity is glitching or I rather know. Some objects like bushes sometimes disappears, objects seems to be over one more layer when they are supposed to be under. These things happen in the scene and when I start the game, everythings turns back to normal. My characters speed changes over time, I have my normal speed virable set to 7 but now when I come back to unity, 7 is way to slow and have to increase it to around 55 to be able to get the same speed as before. After some time though the speed goes back to normal and 55 becomes waay to fast.

So I can probably think it takes some time for unity to get warmed up? If this is the case then how can I get it to work faster?

One more thing is when I walk with my character, sometimes when I walk left or right my characters goes under some layers all of a sudden. This happens only sometimes and sometimes everything works fine. And I just created another room in my 2D game and in that room when I go left my character disappears but it still walks.

Is there anyone here that knows how to fix this? I hope that I explained it good enough for people to understand what I’m dealing with here. xD
My specs on the computer im using is:
processor: AMD Ryzen 7 5800H with Radeon Graphics 3.20 GHz
Graphic card: NVIDIA GeForce RTX 3080 Laptop
Ram: 16gb

I solved it for now… It had to do with sorting layers xD… All though the character speed differs from time to time and when the character walks it is a bit choppy… Is it possible it is just the unity engine that is slow and will work as it should when you make it into an actual application?

I still think there are some settings that could make unity work faster or peform better? If there are then please tell me what settings are recommended!