I recently encountered a glitch in a few ragdolls I have. Whenever I spawn some, they’re stuck in their t-pose and stiff as a board, with the space below them solid for some reason. GMod also seems to read them as props, as evidenced by it saying “Undone Prop” whenever I undo spawning them.
This doesn’t apply to all the ragdolls I have. Just specific ones. The ones I do know that have this glitch are the Left 4 Dead survivors and an Angel Beats character. This bit of info might help find out the problem.