Airpods lose sound with Zoom/Google Meet on iMac (but not Windows, Chromebook, iOS)

When I use my AirPods for Zoom or Google Meet calls with my iMac (Retina 5K, 27 inch, 2017), the sound gets staticky and stops after 10-15 minutes. Others on the call often say that my microphone cuts in and out when I speak. This is despite Bluetooth showing the AirPods are still connected. This problem began sometime in 2022. I used these AirPods successfully with this computer from 2019-2022 on multiple videoconference calls using Teams, Meet, Zoom, and other services (I work in Telehealth).

I have two sets of AirPods, and they both have the same problem. I have reset and unpaired them various times, but it does not help. These same AirPods have no problem staying connected during video conference calls with my work Lenovo Windows Thinkpad or Dell Chromebook. If I use the AirPods to listen to music or other sounds on my iMac, they stay connected without issues. The AirPods work well with my iOS devices.

I used the ToothFairy app to "improve sound quality by disabling audio input from device," but this only helped temporarily with the microphone issues.

I don't know what is wrong with my iMac's Bluetooth, but other than the usual rebooting, unpairing/pairing, and following each service's recommendations, I am unsure what else to do.