Problem with template functions and library maintenance

Hi,

As I'm much more fluent in python language than template definition, I have a lot of template functions that I call directly in custom columns. I've seen today that, after a library maintenance, the custom columns get broken because the template functions disappear (they are not there when you go into Preferences->Template functions). If you change the library and go back again, the functions are already there.

Is this normal?

Thank you