Classic extension in crashloop in Firefox

The 1Password Classic extension is stuck in what appears to be a crashing loop. The browser toolbar icon flashes and then goes grey around once per second. Cmd-\ just brings up a dialog telling me to add 1Password to firefox. Clicking the toolbar icon does nothing. The option to remove the extension is disabled (I have to manually delete it from the profile folder). The 1Password application is running and (as far as I can tell), healthy (it's how I logged into these support forums to paste this!)

Using firefox's extension debugging tools I see these logs in the console for 1Password

Finished loading auth configuration. Processing callbacks. global.min.js:88:471
[CHROME:NM] Port <[object Object]> disconnected: No disconnect message global.min.js:249:130
[AGENT] Connection [object NativeMessagingConnection] disconnected. global.min.js:105:465
1Password detected a high number of disconnections from the browser extension to the main application between Tue Mar 22 2022 12:42:36 GMT-0700 (Pacific Daylight Time) and Tue Mar 22 2022 12:43:14 GMT-0700 (Pacific Daylight Time) global.min.js:249:479
[AGENT] Connection [object NativeMessagingConnection] disconnected.

Identical blocks of logs show around once per second.

In case it's relevant, I also see a warning for 1password in about:debugging#/runtime/this-firefox

Reading manifest: Warning processing key: An unexpected property was found in the WebExtension manifest.

This is with macOS 12.2.1, Firefox 98.0.1, 1Password 7.9.2 and version 4.7.5.90 of the classic extension.

1Password Version: 7.9.2
Extension Version: 4.7.5.90
OS Version: macOS 12.2.1