Flying in survival when use /gamemode s

1. About this glitch this glitch started from version 1.16.10 until version 1.17.11 hot fix update.
2. When you you in creative and then go to survival using the /gamemode s and the the world started to very lag and when you in survival you can fly.
3. I reported this glitch because this glitch like hacking so that why i report this glitch
4. Hope you see the video that is the proof.
5. Hope you fix it Mojang.
6. Bye.