version 1.16.1 server 

player is operator

Tnt is not causing damage to the player who ignites it.
NOT on peaceful mode.
Can still take all other forms of damage.
Indirectly igniting tnt will damage the player.

Can't reproduce, so video is included as well as other info.

I can't seem to find anything similar to this issue, and am unsure of the cause. 

Can't reproduce in single player, or with another new server. copied server properties over to the new server folder, and changed keep inventory to true so all settings would be identical for testing. I have disconnected and shut down the server but the issue persists. I attached 2 videos with gameplay showing it, and a crash log. I included F3 info in the videos, as well as showing the difficulty (hard). I wasn't sure of anything else to add, but I'll update the ticket if needed.

(Longer bug video: https://youtu.be/GDoEhdlKMBU )