If you use the Google Play Store to install apps on your Samsung Galaxy Note 9, they will be automatically updated by the "Auto Update" feature of the App Market when a newer version is available.
The W-Lan network or mobile data network is used for this purpose. If you do not want your apps to update automatically, you can disable these auto updates in the Google Play Store settings as follows:
Open the Google Play Store on the Samsung Galaxy Note 9
Tap on the icon with the three lines in the upper left corner to open the menu
In the menu sidebar that opens, select "Settings" from
In the "General" section, select "Automatic App Updates"
In the drop-down menu, activate the option "Do not allow automatic app updates" (scroll up in the mini-menu).
You have now successfully deactivated the automatic updates for your Samsung Galaxy Note 9.
This means that apps are no longer automatically updated to the latest version and you are now responsible for installing updates yourself.