Issues streaming from my Plex server to remote client

I’ve been having some strange issues streaming to remote plex clients. Some movies stream fine, some can’t even get started without saying the connection isn’t fast enough. My internet connection is a 100/10 Spectrum business connection, and my plex server is a CentOS VM with 6 vCPUs and 30GB RAM, using a RAMDrive for transcoding, and I’ve tried transcoding limits of 8Mbps and 4Mbps, and regardless of which setting I set it to, some movies will play fine while others won’t play at all. And the strange thing is some of the movies that won’t play were ripped from DVD, while some of the movies that will play without issue were 1080p rips from BluRay. Within my local network, nothing has any issues whatsoever playing.

Any ideas why some movies, even with the bandwidth limit set WELL below by outbound speed, just won’t play for remote clients, while other movies are fine?

No one has any thoughts on this?