Running into this issue as well on RC 11 but it's been an issue for awhile now. Websites like Disney+ and Formula1TV (https://f1tv.formula1.com) never play anything.
To reproduce: select a video on Disney+ to watch, it then loads up the page for the video but it never starts playing it just sits as an empty screen. On Formula1TV the page will fully load for the video but video itself will just remain an empty box.
Tested with compatibility mode and it doesn't work but I tested in a completely clean profile and it does seem to work.
Orion Version 0.99.126.4.1.11-rc (WebKit 619.1.1)
MacBook Air M2 with macOS Sonoma 14.4 build 23E214