Yep that’s it Steve.
I’ll confess with a story from when I began to use a funnel. After a few days I had 12 bar or more shots and couldn’t work out the problem and contacted DC who in usual generous style was racking his brain trying to remotely diagnose the seeming-cavitation problem, and I think even asked me at the beginning an important question and got the wrong answer from me. Having reached the point of puzzlement he asked me again if I was sure the water inlet pipe was immersed in the reservoir water which I now checked more carefully and to my embarassament it was not, yup that will do it he said pondering over his wasted time no doubt.
Evidently what had happened was that each time I refilled I was lifting the inlet pipe a couple of millimetres and forgetting to push it gently back down, I marked the correct position at lid height with a pen for a while and watched hopw easy it was for it to happen until it was second nature. So, funnel is my preference but for ayone who also likes the idea, take it from a numpty, just make sure you pay attention to the inlet pipe!
