I’m about to head to sleep, but if I may ask, what operating system are you using? (Windows, Mac, other?)
It currently is working here, but here’s some things I can recommend for now:
Do you have any extensions installed in Brave? (If so, any installed in Brave that aren’t in Chrome, or the same?)
Try going to Settings > Privacy and Security > Delete browsing data > Only check “Cached images and files”, nothing else, and set Time rane to “All time”. Does this improve?
Repeat step 2, but include “Cookies and other site date” but warning: you will be signed out of everything you are signed into. Unlike Firefox, Chromium based browsers such as Brave (and Google Chrome) you can’t selectively remove cookies from one site only, so if you do this step you will be signed out from everything.
Also, do videos on other websites play? If not, this is one of those times I would recommend trying for troubleshooting: Settings > System > Turn off “Use graphics acceleration when available”. Does this make videos play? (I know it may be choppy but we want to get playback.) If so, you might want to try updating your graphics driver.
This step is optional as most people don’t have super high end sound cards (so if you don’t, don’t bother reading this step, you won’t have this sampling rate, only specialty cards have it) like I do, but this setting on Windows 10 at least, will absolutely cause what you are explaining: Control Panel > Sound > Right-click your sound output, Properties > Advanced tab > Ensure a sampling rate of 352800 Hz or higher is not selected. Windows 10 cannot resample this and playback won’t work and cause videos to simply not start playback. Windows 11 (latest version) can do this with Brave, this is is only a special case. (And I only added it since I’m heading to sleep and just throwing troubleshooting options until I wake back up).