Service receptioon told me part of the 5.4.3 “upgrade” is to help with the 12v issues.
From what I’ve seen online the new 5.6. hasn’t improved things or addressed many of the other issues owners have asked for.
See https://www.youtube.com/watch?v=1vOwbNiUGTs
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!