Ah! You need to make sure that all animations go in phase. So, when you start playing the animation you’re going to blend into, make sure that the phase of the animation is the same.
If all animations use the same length (walk/run/skip/whatever,) then syncing the playback time should be enough. If they are different lengths, you have to pick the right point in an animation to blend to the next one; typically by tagging points in the animation with “transition here” markers that your animation blueprint then looks for and uses to switch anmiation.