Thank you for your authoritative comments.
I found the source of the problem.
During programming, some data that should not be written to the EEPROM is written. For this reason, an error occurs during Verify.
And the programming cannot be completed.
If the EEPROM option is not activated before programming as you suggest, the programming is completed without any problems.
Note: This issue only exists with the T48. No problems with the TL866II plus.
