I am not sure it’s a bug or not.
I have a simple form F with a text field T and a custom button B.
B is linked to another app A, passing to A, as a parameter, the value of T.
B is visible on the form both in update and insert mode.
I am experiencing this weird behaviour:

When F is in insert mode and I enter a new value for T and afterward I press B (without inserting the form) then A does not receive the value of T, despite T is displayed on F.

When F is in insert mode and I enter a new value for T and insert the form and afterward press B then A does receive the value of T as expected.

When F is in update mode and I press B without changing T then A does receive, as expected, the value of T as displayed on F.

When F is in update mode and I change the value of T to a new value and afterward press B (without saving the form) then A gets the old value of T but not the new valued of T displayed on F.

When F is in update mode and I change the value of T to a new value and save the form and afterward press B then A still gets the old value of T as in case 3.

When F is in update mode and I change the value of T to a new value and save the form and force a reload of the form (by moving to another record and then back to previous record) and I press B then A gets the new saved value of T .
It seesm that A gets the value that was initially loaded in F the first time.
Does it make sense ? Is it a bug or not ?
Thanks a lot for your help.