When i plug my spektrum servo into the s6000 receiver it has no issues but when it come to the esc throttle plug it wont fit. Seems like its a square plug and the spektum servo is angled on one side

cut it with an xacto knife. Make sure to not expose any metal wiring.

I ran into a similar issue with a HW ESC into a Sanwa receiver. I tried to shape it a bit with a Dremel and a file and then eventually got it to fit. I thought this stuff was in universal.