Found while testing the now "fixed" MC-60933.

When standing inside of fire in Creative mode, the player sets on fire despite being immune to it. This behaviour is onconsistent with other mobs that are immune to fire such as zombimified piglins, which do not display as on fire under these circumstances, and also somewhat disruptive as the fire overlay is completely unneccessary (fire isn;t harmful in Creative so why should it be there?) and blocks out a lot of the screen.

This behaviour has also affected lava for years now and should probably be removed from it as well for Creative players, since fire-resistant mobs don't show the fire animation for this either.

All of these probably also affect players with fire resistance.