Graphics-related crash when switching applications away from AE

Frequent (every session) crash when using AE for the last ~3 2021 updates and Beta. After working in the timeline (scrubbing is sufficient), any attempt to switch to another application causes a system freeze of 2-5 minutes. If I wait it out, the comp window in AE becomes solid white, and I am able to access other apps. AE doesn't recover; to get the comp viewer back, I have to quit and re-launch.

Steps to reproduce:
    1.Open AE and move around in a composition timeline

    2. use alt-tab or windows taskbar to select any other running application

 
Result: system hangs for 2-5 minutes; mouse and keyboard unresponsive including to ctrl-alt-del. At the end of the freeze, the AE comp window turns white and system responsiveness is restored.
Expected: should just switch aps, no?
 
System info
    Application: After Effects (Beta) v18.4.0.18
    OS: Windows v10.0.19043, RAM: 255.89 GB, CPUs (logical): 64

Video NVIDIA GeForce RTX 2080 Ti v.27.21.14.6259 (2 installed, with NVLink)

May 2021 Studio Drivers
--- GPU Computation Info ---
Found 2 devices supporting GPU computation.
CUDA Device 0
Name: GeForce RTX 2080 Ti
Vendor: NVIDIA
Integrated: 0
Capability: 7.5
Driver: 11.2
Total Video Memory: 11264MB
CUDA Device 1
Name: GeForce RTX 2080 Ti
Vendor: NVIDIA
Integrated: 0
Capability: 7.5
Driver: 11.2
Total Video Memory: 11264MB
GPUSniffer process exiting after 3095.53 ms
GPU Sniffer result: 30