Publisher does not save changes in non default languages for any text field or textarea except text fields or textareas in grid fields.
Steps to reproduce:
install ExpressionEngine 5.3.0 with default theme.
Install Publisher 3.0.0 with bilingual setup.
Create entry in about section in default language (german)
Create translated version of the previously created and save it
Result: all changed i made within grid fields within translated version stick.
All changes i made within standard custom fields or standard textareas not sitting in grid field do not stick but are reverted to the default language version.
I have encountered this problem on all client websites where i use publisher.
To narrow down and to replicate buggy behaviour i have created the test ExpressionEngine (see credentials attached)