A small update has started to roll to the Sony Xperia Z5 range which moves the build number from 32.2.A.0.253 to version 32.2.A.0.305. This remains Android 6.0.1 Marshmallow firmware, but hopefully has provided more up-to-date Android security patches – the previous firmware only updated patches to April 2016. If you have downloaded the update, feel free to post some pictures and comments below.
Thanks Simon!