g-kats

You most likely have the condition lever mapped to something. Mine was on my speed brake axis binding, which was a somewhat spicy landing.

I believe this is more prevalent if you start engine 1 first.

...and gone again. It's definitely intermittent.

This has come back again for me.

I have loaded max fuel, max pax and max cargo (this EFB slider allows you to load more than the FMC will permit you to enter (15 tons). Have pressed Apply button. Fuel loaded in overhead display is some way short.

Flew a short sector EGSS to EGSH, FL100, was getting random CABIN ALT WARNING messages, including on final at < 2000ft

As title, there are no touchdown sounds at all.

A force-redownload has cured this problem for me

Yes I've found the same issue.