Arduino for STM32

Hello.
After a long time I come back with a problem.
I noticed that after several saves in the same or different location, no more data can be saved, when I read the eeprom all the addresses are... 65535. I can no longer save until ... Full chip erase.. . in the STM32Cube programmer, after that you ...

Hello
I read it here first...
https://randomnerdtutorials.com/arduino-eeprom-explained-remember-last-led-state/
I wrote like that...

#include <EEPROM.h>

int a = 0;
int value;

void setup() {
}
void loop() {
value = EEPROM.read(a); //citire eeprom
Serial.print(a);
Serial.print("\t");
Serial ...

libmaple is ok, and decently lightweight on stm32f103, but it is mainly designed around stm32f103.
for the gps and eeprom, I'd suggest get a better board and run the 'official' core
https://github.com/stm32duino/Arduino_Core_STM32
boards could include things like Nucleos f401 or f411 RE boards ...

Happy Birthday !..
I have stm32F103C8T6 ... blue pill ... Arduio IDE.
I'm still trying to save GPS data to EEPROM and I can't do it at all. The data appears on the console and on the LCD. Does anyone have the patience to help me?
I've tried many eeprom emulators ... and nothing ...
Thank you....
Be ...