Do you lock the new value with TAB after changing the value?
Yes I used the tab key, but the value is reset to 0 (zero) after a few seconds
Use windowed mode. Full screen seems to have issues.
Has no effect.
try cleaning out any old trainer data windows may be trying to use instead of generating new files.
Delete trainer and all files in
C:\Users\USERNAMEHERE\AppData\Local\Temp
C:\Users\USERNAMEHERE\Cheathappens\Work
C:\Users\USERNAMEHERE\AppData\Roaming\Cheat Happens\0x90
C:\ProgramData\CheatHappens
Learn how to make your own Trainer Cleaner for the above paths Here. Link
Reboot PC to clear excess memory, get a fresh copy of latest trainer and extract it. Run trainer as admin, read the instructions and try again. At times, a new game may be needed to resolve failed options if the data in your save file was altered. Use on a new game and test the option. If it now works, quit to main menu and load your save and try it again. May also need to run the game without the trainer first and play a bit so the save file gets updated to use possible new values.
Unfortunately no success. The value is immediately reset to 0 (zero) after I press the tab key.