DSC, "spitting" sounds like channelling. Despite your best efforts, the water is finding a weak spot through the puck.
From your description youre doing things pretty right. Colour is good. But Id do one or two modifications.
Having put the appropriate dose into the basket, and levelled it, allow the weight only of the tamper (assuming you have a heavy one) slightly compress the grounds.
Then remove it and give the side of the basket a very gentle tap to make the grounds clinging to the sides fall in.
Now do your 14-15 kg tamp, polishing at the same time, not after.
But from that photo it all looks good. Whats the taste like?