Hi,
It sounds like the issue might be related to the video quality. If the bitrate or resolution is too high, some lower-end devices may struggle to play it smoothly. You could try re-encoding the videos using a tool like HandBrake to make them more compatible.
If you are on Mac and familiar with the terminal and Homebrew, then you can install Handbrake via terminal
brew install --cask handbrakeYou can find a guide on this here: https://playsignage.com/support/handbrake/