Hey there Chris-so,
Thanks for reaching out to the Apple Support Communities.
If having issues with media not playing as expected on your MacBook, make sure you've checked out the steps listed in the related article you used to reach Apple Support Communities: If a media file doesn't open or play on your Mac, iPhone, or iPad - Apple Support
Apple apps such as Photos, iMovie, Safari, Keynote, and QuickTime Player work with many media formats. Some apps prefer specific formats, but most formats work in most apps without additional software. Older or specialized formats might not work as expected if your device, its operating system (macOS, iOS, or iPadOS), or the app you're using to view or play the file doesn't support the file's format.
Install all available software updates for your Mac and software updates for your iPhone or iPad. After updating, if you still don't have an app that supports the media format used by the file, search the internet or App Store for an app that does. You can search by the name of the format, or by the filename extension, which is the letters shown at the end of the file's name, such as .avi, .wmv, or .mkv.
If still having issues after going through the resource above, reach out to Apple Support directly at this link here: Get Support - Apple
We hope that's able to help.
Take care.