Frame.io panel playback: Makes Program Monitor play very jerky and it won't stop playing!! Ever!

k I can fly through my timeline without a single drop frame - at 2x, 3x, even 4x speed - even in reverse! But as soon as I play the (timeline synced) video in the Frameio panel in Premiere, the Program monitor is not only disgustingly jerky and unusuable, but when I stop playing, Premiere carries on (very jerky) playing (in the Program Monitor) for ages - sometimes several minutes. Making This experience completely useless and unusable for me.