The first thing I would do is get the installer back to repair or replace. You may have installed yourself, in that case you will have to check the connections are fully located etc.
You say installed October 1st, that means you have no problem getting the installer back as they are responsible, or take it back to the retailer if you have checked everything is connected correctly. Don't waste your time for an answer on here, as those options are far quicker.
Thanks for posting.
We appreciate the help, Frustratedddd.
NikChele, could you restart your Nest Thermostat and check if it will still show the same display issue? Check this link to know more.
@NikChele how's it going with your Nest Thermostat? were you able to perform the steps suggested above? We'd be glad to hear from you — We'd like to make sure everything is working.
Thanks for answering, Mel and Frustratedddd.