Unexpected change of static pointer values

[another_esp_user]

I am new to C and esp..
I encounter a weird situation building app with lvgl(don't know whether it is the cause).
The thing is I declared a global static function pointer in one of my .c file and I only assigned it once(with a function declared in a included header file). Then I used a task to print the value of this pointer. The console printed the values of this pointer and it kept changing while there is no more assignment of the pointer in my code other than the one I mentioned before and it only happens when I use lvgl..

I did a small dummy program with global static pointer and it is ok the address didn't change..

I am wondering whether it is possible that lvgl somehow override the value of my pointer ?
I am very confused now can someone help me ?? the problem is in display.c

navigator.zip

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File attached is my project..any advice and suggestion is appreciated not just this problem but also other suggestion about the coding style and usage of elements of C in this project. I am not very familiar with C.