Appium chromedriver error: "Process didn't end after 10000ms" after switching to webview context

We are testing an Android Cordova application in Device Farm using Appium. We use the hack from here to get the chromedriver working on AWS: https://forums.aws.amazon.com/thread.jspa?messageID=983382&#983382 . This has been working well until recently. We are now getting this error after switching to the webview context:

[0-0] 2022-01-14T16:27:50.188Z ERROR webdriver: Request failed with status 500 due to unknown error: An unknown server-side error occurred while processing the command. Original error: Process didn't end after 10000ms (cmd: '/opt/chromedriver/linux/65/chromedriver --url-base\=wd/hub --port\=8000 --adb-port\=5037 --verbose') [0-0] Error in "chat landscape can send chat messages in landscape" UnknownError: An unknown server-side error occurred while processing the command. Original error: Process didn't end after 10000ms (cmd: '/opt/chromedriver/linux/65/chromedriver --url-base\=wd/hub --port\=8000 --adb-port\=5037 --verbose')

Restarting the unchanged code that has been working before now keeps returning this error. The only thing that changed is that we bought a Device slot on Device Farm. Does anybody have any clues?