My laptop switched from AHCI to RST on its own (probably after a Windows update) and now I cannot boot my Kubuntu anymore. Live sticks also cannot access the drives. When I try to switch it back in the UEFI settings, it tells me that it will wipe the drive to do so.

Is this message correct? How can I change it back without losing all my data?

The device in question is a Lenovo Ideapad 720-15ikb with Kubuntu and Win10 dual boot.