What does your Monroney sticker say?
EDIT: You got me curious, so I went out and checked mine again. The "Tesla Information" section on the main MCU screen shows the model as a Long Range Plus, but the instrument cluster still reads "Long Range". Interesting.
This is how mine was delivered. After a few reboots, that instrument cluster finally showed long range plus. Still waiting for the latest firmware to close my range issue. But based on other feedback and words from Tesla, I’m confident this will be my fix.