Hello.
Using the "flash_write_page" API function, data is written and read in the user area.
However, the data is not written properly intermittently, and the previous data remains intact.
I have a few questions about it.
The module is always receiving a power supply of 3.3v. Do not use low voltage or sleep mode states.

Q1) Do I need to erase before using the "flash_write_page" function?

Q2) Is verification performed on the data being written within the "flash_write_page" function?