Is this a problem with my lens or camera

[jaomul]

You're very welcome, but that still seems odd; WHY should shooting at base ISO -1 render highlights with such an odd colour cast??????

I am not sure but googling it turns up a few results. It seems not uncommon with Panasonic cameras and "some" raw converters. Tbh I don't ever need to be at low expanded iso. I'll try the raw files in few other converters when I get a chance