I have just received a land tax bill for my primary place of residence, I purchased the property a little over 12 months ago. I know I'm not liable for this as it is my primary residence which I can easily prove, but why would the OSR have assumed it is an investment property? Would it be something incorrect with the settlement documentation? From the time of purchase our intention has always been to reside at this property.
I agree it seems odd. Settlement sheet information should not alter based on your intention.
Perhaps the previous owner was liable for land tax and the OSR continued thinking it was liable for land tax.