Thank you for contacting Cypress Semiconductor.
I would first like to point you to the following AN (link) which is a migration guide for GL-P to GL-T migration. Please go through and make sure all requirements have been met for the migration.
- I would like to point out that the Vcc Setup Time to first access (tVCS) is different for both devices. GL-T needs more time for setup.
- I would also like to point out that the single word program time for GL-T is greater than that of GL-P.
- Could you please tell me the locations where the word programming is failing for either of the devices?
- Could you try to read the Status Register value after programming operation completes and tell us the result?