Yep, simple problem, simple solution.
What I did for reference, was this:
Space bar pressed → jump → custom RPC (Run on server) which sets a replicated bool (isJumping) to true and sets it back to false after a delay
In AnimBP, onUpdateAnimation “tick”, check to see if isJumping is true and if it is, do a multicast RPC event once (reset on isJumping is false). This multicast plays the jump animation, and I handle landing with branching points in the montage.