Thanks for reaching out.
Could you share your system specifications (CPU, GPU, RAM, OS version) and the exact version of After Effects? Also, let us know the version of the GPU driver installed on your computer. Here's how: https://support.viewsonic.com/en/support/solutions/articles/33000221571-how-to-check-graphics-card-d...
We're here to help, just need more info.
Is this happening all the time? Have you tried creating another comp? What if you create another Project?