Decline of performance on macbook

Hi, i have a Macbook pro 2019, i was creating a landscape in 5.1.1 with many animated trees (minimum 50) and the performance in high standard scalability was good. I wanted to have a high quality preview of the landscape and I put all the graphic settings to the maximum (Included texture and render engine). Obviously the performance had dropped drastically, so I decided to return the graphic settings to standard but the performance did not improve. I uninstalled and reinstalled the engine to reset the settings but nothing changed. How can I fix it? There are some standard settings that i can put?