I am experiencing the same problem on both my iMac 27" 5K (2017) and my MacBook Air (2017). Both have Intel i5 processors and plenty of RAM. Both are running Monterey 12.3.1.
I've been using Stellarium on both for two years. This issue cropped up after installing 0.22.0. 0.22.1 shows no improvement.
For me, the Oculars plugin seems particularly affected by this.
Best regards,
Tony