Error replacing hard drive with identical drive: "Device too small"

[lajo001]

Hi,
I'm replacing a faulty Seagate Ironwolf 8TB drive with a new Ironwolf 8TB in a 6 drive RAIDZ2. But I get "Device too small".
The first drive was VN0022, the new VN004, i.e. a few years between them.
Are these drives in some sence different in a way that the system finds the new as being too small?

Running 12.0 U1.

Or is this a bug?

 

[lajo001]

Upgraded to U5, now working...