Thumbnails show up very slow

I have some hours of footage in different events of my library and working extensively with the thumbnail view with the event browser almost in fullscreen view. But everytime I click on a different events it takes a long time for those thumbnails to show up. Even if I click on another event and immediately go back to the first one it takes maybe 30 seconds for those thumbnails to show up. My cache folder is on the local SSD of by MBP M2 32gb ram and its not synced by any cloud service or timemachine backup - which could slow things down. is this to be expected?