I'm having this same problem. Have tried reinstalling the current version of Meetings and no luck; it still can't find my camera. Have been looking for a download link to reinstall the one version of Meetings prior to the current one, but cannot find it anywhere. (I'm also on a Mac). Can anyone help to provide a link to this?
Kindly remove the existing RingCentral Meetings (RCM) App and install the RCM Logging version
here then replicate the issue. Please collect the app logs and screenshot then send it to RC Support so we can have our Dev/Product team investigate the cause of the issue and provide a permanent fix. Installing the older version of RCM is an option but not recommended.