Ender-3-v3-se Hot End Issue

HELP, i’ve installed a new Hot End in my Ender 3 V3 SE due to the old one simply not working causing a jam and now the new one has done exactly the same.
Did a std extruder when inserted but then failed to print.
I attempted to print the “cat” but it wouldn’t even do that.

So after disassemble, clean, remove crap, reassemble, now it works … go figure :roll_eyes: