The post edit page does not save the modified date. It does however save the lock. Verified with [https://playground.wordpress.net/?plugin=wp-last-modified-info](https://playground.wordpress.net/?plugin=wp-last-modified-info) See [https://wordpress.org/support/topic/post-modified-date-will-not-update/#post-17979016](https://wordpress.org/support/topic/post-modified-date-will-not-update/#post-17979016)
The post edit page does not save the modified date. It does however save the lock.
Verified with https://playground.wordpress.net/?plugin=wp-last-modified-info
See https://wordpress.org/support/topic/post-modified-date-will-not-update/#post-17979016