I'm basically duplicating a question raised @ FreeChat section - there is a problem with using Nextion screen connected to arduino when NexLoop (Nextion library for arduino) is used in main arduino loop together with other commands. More information from few users experiencing the same issue under link below:
I'll be very grateful for some suggestions!!!
I will apologize for any past delays in receiving responses.
The ITEADLIB is being worked on as an ongoing process and provided as some semblance of an example. Although the ITEADLIB was released, official support is limited to Level 2 to ensure the Nextion hardware works.
Coding questions and techniques should be posted in the Free Chat section where other users can try to assist with any Arduino related items (of which, you will see we try to assist where we can as well)
As this is not a Nextion Editor bug or a Nextion device bug, this topic will be marked as closed.