Not with every update, but mainly when there is a new version that requires updates like this. Since you have to uninstall the old versión, the data (including save files) is also deleted. You can move the save files using data explorers (external ones, not the one that comes pre instaled), but it is a pain, and sadly since it seems like you already unistalled the previous versión I think you can't recover your save files anymore anyway, but something to keep in mind for the future
ok, so I don't remember exactly how to do it, so you should search how to move save files on ren'py on android, and you should find a proper explanation. First you should download a file explorer (Quick search says that Solid explorer is good) then you go to the folder that says Android, then data. Then you search the folder of the game ( in this case i think is called lust.odyssey) and then you just go to saves and copy that. Then you uninstal the game, instal the new version, and then paste the save folder in the game files again. This might not work anyways? And it is way easier on pc. I just remember the last time I had to do it was a pain lol