Lightroom works slowly on Mac

Hi,

I got some issues with Lightroom on my iMac.

When I use masks or correction brush while processing high resolution photos, it starts to work terribly slowly. The same problem occurs when switching between photos (it takes 5 seconds and more), which is frustrating.

Changing the photo correction settings such as exposure, contrast also has a slight delay, but it's not that much of a hassle.

I have the latest firmware and system updates.

I'm working on:

- macOS Monterey 12.6.7

- iMac Retina 5k 27"

- Intel Core i5 3,2 GHz quad core

- RAM 24GB 1600MHz DDR3

- AMD Radeon R9 M390 2GB graphics

The problem was already present in older versions of Lightroom. I tried to change anything in Preferences / Performance / Use Graphics Procesor but problem is still the same.

Turning on and off synchronization doesn't help...

I have Adobe programs installed on the OS partition, and I store and process photographies on another partition.

Camera Raw in Photoshop does not have this problem at all. Everything works so fast and smooth even working on 46MP photos.

What could be causing this problem?