User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Steps to reproduce:

This problem occurs all the time.

Actual results:

I am using Linux Mint 21.3 Cinnamon 6.0.4 on a PC and a laptop.
I click on a video and sometimes it will play fine at 720p. (Firefox set on Auto).
Click on another and I get constant buffering circle and video never plays.
Sometimes video starts buffering part way through and never recommences unless I click further up the time line (this does not always work).
Less of a problem on the laptop but still occurs.
My internet is high speed, problems do not occur when using Chrome on Linux Mint. No problems with any browser if using Windows 10 or 11.
Streaming youtube, Netflix etc on my TV never buffers.
This is only a mint/firefox issue.

Expected results:

Videos start promptly at at least 1080p and will play at higher resolutions if available.
Little or no buffering.

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: Playback' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

This sounds like bug 1878510.