ADD icon in rich text field disappears before I can select any media to add

Hello. I have a rich text field in my CMS collection template that is properly connected and was working perfectly. There is already one image that is displaying correctly and I can still add text. However when I click on the + icon to add media, the options appear and then disappear immediately - before I can move my mouse to select image or video. I’ve tried logging out/in, restart my laptop (Mac OS) and I’ve tried in Chrome and Safari. HELP!