The A7 saga continues...
I made a note of my custom menu settings and then did a reset. Thankfully all my custom menu entries were still there but some settings had changed, that's all. The bad news is that the focus it still off at f1.8 and close distances with AF-S and DMC and consistently so. Just to be sure I turned face detect off but that made no difference. At longer distances any slight errors can be covered by DoF even at f1.8 but at close distances problem this matters to me as when out and about I often take pictures of flowers and leaves and other detail and this is when it's going to show up.
I can't think exactly when this happened. I'm pretty sure my Singapore holiday pictures are unaffected but they were at f2.8 so I can't be sure. I have taken quite a few close up pictures with the 35mm f1.8 since I got it and I don't remember any issues so I think that whatever has cause this has caused it recently. The camera hasn't had any bangs or bumps and all that's happened recently is the time/date/region loss. I'm also puzzled at how this can happen with a CSC taking focus off the sensor.
The camera is on version 2.0 and Sony have 3.2 available so I'll give that a go with fingers crossed but I'm not too hopeful