Reproduced on my end several months later, for both chrome and firefox versions
Version 0.99.125-beta (WebKit 616.1.22)
Build date Jul 31 2023
MacBook Pro (macOS Sonoma 14.0 beta build 23A5312d)
The extension popup does show up for both versions (chrome's didn't before, and other extensions don't show anything). But there should be a stream detected given the website/video that I'm playing (tested with firefox, edge, brave).