Insane chatter / jumping when jogging x and y

[sugarl14 (Landon Sugar)]

My issue seems to be similar to this guy’s issue

Bit grabbing? Cuts destroyed

I should have mentioned that although the setting says 1/4" for the name the bit is actually 1/8" (3.18mm). The bit has a 20mm flute and the total cut depth I’ve been using is 19mm which gets it just through the 3/4" plywood. It is 90deg to the spoil board (1/4" MDF). It gets about 10mm into the board before it goes nuts… So I went and removed the router and the mount. I found the mount part on the Z axis a tiny bit loose so I tightened the crap out of it. Then I reattached the router moun…