Missing media codecs?

So I’m trying to play some mkv files and whilst some will play fine, others either outright won’t at all or they’ll just play without sound. I get a message in Dragon Player that I’m missing codecs. I also note that installing VLC doesn’t help as it suffers from the same issue. I also note that I have made sure (as far as I know) to install all relevant gstreamer packages which has made no difference to my issue. These are files that play perfectly fine in VLC under windows.

What am I missing?

Have you installed the RPM Fusion repositories? And followed their HowTo for multimedia codecs?

Yes, I had installed the rpm fusion repos previously.

I checked out that other link you posted and after I executed the command “sudo dnf swap ffmpeg-free ffmpeg --allowerasing” and went through the various prompts, everything seems to be working now. Thanks so much!