When shaders are enabled, the characters hand shows regardless of the visibility setting in the player-overview.

Tested so far:

• RM 2.6.13 on MC 1.19.4
• RM 2.6.13 on MC 1.20.1
• RM 2.6.12 on MC 1.19.4

All of those always show the hand with shader, but toggle correctly without

I think it's because the Replay Mod doesn't render any GUIs (which is what the shaders are toggling), but it renders the actual player with the hand in view. If you don't want the hand showing I think you could go to the player overview and disable your character.