seems trying to change the charictor movement component at run time is not the right way to go about this
as it affects other charictors and creates issues with server client replicate movements
but i did find a work arround for walking at least
what you need to do is set the default char walk speed to be the max rate it will ever move (this also affects all pawns of the same class )
then edit the controler for that pawn be it player controler or ai and find the pawn movement inputs
and scale down the input scale values
in the case of the bp above i get my player fitness value (between 50% and 200%) / 200 to give a value between 0.25 and 1 and multiply this by the scale value from the player controler input
this limits the max movment speed from the analog sticks to a percentage of the max movment rate of the player without affecting other players or ai
although you will need to scale the inputs of those also according the the max movment speed you wish them to be at (as otherwise they will all be the higher default movement speed)
ie if you set the movment speed component default to 1600cm/s as 200% in the example above 100% fitness limits it to 800cm/s
also as this is done in the usual player controler /ai controler BP it does not need the overhead of event tick’s to change the movement components
and you can then change the movment rate percentage on the fly per charictor at run time by changing the fitness varible in the player controler( ok so i pull the value from my main game stats saved game varibles )
(just need to find a way to do the same for jump now )