Finterpto isn't working

Has anyone else experienced difficulty with FInterpto? My current and target values can and do change at runtime, and it picks up on that and the output value adjusts accordingly, but no matter what I do with the interp speed and delta time, it just abruptly changes values as opposed to transitioning smoothly like it should, I believe it’s because when the target value changes, it just jumps directly to outputting that value, rather than transitioning to it from the current value. It’s been stumping me for longer than I’m proud to admit.