Photoshop slow: "transforming" the preview lags behind.

[N_CH]

Hello, I have been working on Photoshop cc (2020) since new, I have a very powerful computer. (Imac 2020, 64 GB Ram, 4TB, 3.6 GHz 10-core Intel Core i9). The newest operating system (Catalania)

The problem: Unfortunately, Photoshop runs very slowly. When "transforming" the preview lags behind. The whole program seems to run much slower than my old Ps Cs6 on a Macbook 2013. Why is the program so slow even though my computer is very powerful?
Thanks for the feedback.

[N_CH]

I just found out that the problem has something to do with "Layer-styles". Without this effect, things run better.