Thanks for reporting! I noticed this too, but only after V1.1 was releases, it was fixed in V1.2 (see: https://timboe.itch.io/factory-farming/devlog/501428/sandbox-mode-minor-update)
Viewing post in Factory Farming (Playdate) comments
Yes, this will always be the case (V1.2 doesn't actually contain any changes to the save game format). Just note that if you originally side loaded before Feb then the you will have both versions installed and will have to copy the save data across to the new version. It might not be worth this hassle for 1.1->1.2, as the fixes are very small.