After upgrade to zfs-2.0.4-pve1 the problem mentioned here disappeared.
same here with proxmox 7.0, kernel 5.11. no smart errors, tried multiple disks.
Note that if you do not use this flag (--raw) for sending encrypted datasets, data will be sent unencrypted and may be re-encrypted with a different encryption key on the receiving system, which will disable the ability to do a raw send to that system for incrementals.
The added security provided by raw sends adds some restrictions to the send and receive process. ZFS will not allow a mix of raw receives and non-raw receives. Specifically, ⚠ any raw incremental receives that are attempted after a non-raw receive will fail ⚠. Non-raw receives do not have this restriction and, therefore, are always possible. Because of this, it is best practice to always use either raw sends for their security benefits or non-raw sends for their flexibility when working with encrypted datasets, but not a combination.