This is not the reason for the absence of kernels 5.10 at startup After the migration to bullseye it was missing update-grub.
- Bug#996018: linux-image-5.10.0-9-amd64: linux/i2c/i2... Jonas
- Bug#996018: Acknowledgement (linux-image-5.10.0-... Jonas
- Bug#996018: linux-image-5.10.0-9-amd64: linux/i... Salvatore Bonaccorso