If you have a file with the "ion265" tag, you need to ensure your hardware can handle it. Because x265 is highly compressed, it requires more CPU power to decompress during playback.
VLC Media Player, MPC-HC, or IINA (for Mac). a teacher s01 webrip x265ion265
Most smartphones, tablets, and smart TVs made after 2017 have "hardware acceleration" for x265, meaning they can play these files smoothly without draining the battery. If you have a file with the "ion265"