More information about this is certainly required to understand your problem.
Which model Nextion, what Arduino, which IDE, what library, how connected?
You can use the Attach a File function in the post to attach video.
And you are pulling the 5V from its own power supply and using common ground?
According to the data sheet, a 1A 5V power supply is recommended.
It is not recommended to attempt trying to pull this from the MCU
Can you post to YouTube?
Please then make a shorter film.
I am trying to assist
Where is your power coming from to power the Nextion.
It appears to be too low of a power supply.
Using a charger 5V 1A and connect only the Nextion with the test plug adapter that is in the box.
As shown in your datasheet for your 4.3 Enhanced Nextion - without the Due
It is not sufficient to just plug in. Actually a hazard to do in this manner.
One must refer to their documentation
You appeared to be powering your Due by USB you do not have sufficient current to supply all the needs from the limited current of USB port.
Also the Due is a 3.3V and not 5V, there will be many issues if you do not heed. The Due can not take 5V on any of its pins, you will need to ensure you are either using 3.3V logic or level shift as required.
Much reading going forward.