Strange jerk or engine movement

Afternoon fellow briskers been noticing something strange on my mk1 vrs, when I'm changing gear say from 1st to 2nd or 2nd to 3rd I'm experiencing what I can only describe as the engine rocking back and forward when dipping the clutch to change gear at low speeds, that might be an excessive description but in my head that's how I imagine it, I changed the gearbox mount and dogbone last year, only mount I haven't done was the engine mount, I'm just wondering if this is the problem, anybody else experienced jerky changes when changing gear? Also get this annoying car wanting to shoot forward when driving slow and in the correct gear that's mostly when it happens and you dip the clutch, driving behind traffic jams for example car picks up speed, dip the clutch and I'll experience that rocking sensation, never really heard much from others complaining of engine mount issues always seems to the mounts connected to the box, thanks