I’ve moved your posts to this topic since we are clearly talking about a FP4.
There’s two reasons this can happen:
- You installed Magisk via a different method than outlined in the forum (e.g. flashed the
boot.imgdirectly) - You updated your Magisk installation to a new version without restoring the image first. Magisk will make a backup of your current boot partition so if you don’t restore before an update you’ll end up with a backup that won’t get you back to stock.
Either way you’ll have to flash the boot.img that matches the Calyx version you currently have installed to get OTA going again.
You answered your own question here, those are incremental updates, they build on top of each other.
(There are also full OTAs on that same page that also only work from one version to the next but don’t rely on the partitions on your phone. Those would work in your case, here’s how you’d install those, but remember backups, backups, backups!)
Don’t! Just get your update procedure in order and look out for Magisk updates, you want those security fixes 