Hello McLarens,
First of all, thank you for your kind words!
There is no need for any changes to be made in order to work with NANO. I am always using NANOs and all the examples are tested on NANOs.
I do not know what could possibly is happening with your NANO. Maybe try another one. Try a common ground between Nextion and Arduino and do not power the NANO from USB when using Nextion.
Also try to not have connected the Serial pins when uploading the sketch.
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