You should not be having transcode issues with anything less than four concurrent streams on that server. https://www.reddit.com/r/PleX/comments/1ae6683/intel_n100_vs_ryzen_7_1700_1st_gen_an_interesting/

It's likely that you have hardware transcoding disabled. Enable it, and these issues should go away. This forum post has good settings in jellyfin for an n100, https://forum.jellyfin.org/t-solved-correct-transcoding-settings-for-the-n100-processor

You should be able to find instructions for enabling hardware encoding in your bios by searching for it with your specific device model.