Strange - auto update from v102 to v115 isn't available, but recent manual check proves it is

When I checked for an update manually, it showed me an option to update from v102 to v115. Since the jump in versions was so dramatic, I did a quick search which revealed that an auto update to v115 wouldn't be available from v102 or prior - a manual download and install would be necessary. However, when I check for the update manually and it shows it's available, clicking the update button begins the download and install process. Is this intended functionality? I want and need a smooth upgrade/update process which won't result in loss of data or complications with my email.