Unable to add IDs to Block and Allow whitelist on Mac client

I'm running 15.19.4 H under macOS 11.4 (Big Sur) on an M1 mac. When I open the Configure... Block and allowlist, I see the usual radio buttons for Deny and Allow, and the Add and Remove buttons. When I click Add the usual dialogue box does not appear. So I'm unable to add IDs/partners.

Seems to be a bug in latest release(s). This did previously work well.

Answers