> For the S10 a mandatory wipe-on-upgrade has last been the case when upgrading from versions _older than LineageOS 21.0_.

Ah, that might be it. My current version is 21.

> If your device is running LineageOS version older than 21.0, wipe your data partition (this is usually named “Wipe”, “Format”, or “Factory reset”) .

https://wiki.lineageos.org/devices/beyond0lte/upgrade/

Yes ! Thank you, I can upgrade to 22 without wiping.