Two different USB 3 HDD docks - disk partitioned on one not usable on the other

I have two different 3TB SATA hard disks:

• a Toshiba DT01ACA300


• a Seagate ST3000DM001.

I also have access to two different USB 3 HDD docks:

• a Connectland DOCK-CNL-YJK3519-V3+ES


• a Focus SATA + IDE dock (exact model name unknown)

It turns out that if I partition a disk on the Connectland dock as GPT with one HFS+ volume, the disk would become unusable when I plug it onto the Focus dock; OS X Yosemite would complain that the disk cannot be read and suggest that I initialize it.

Same thing the other way around: if I partition a disk on the Focus dock, the disk would be unusable on the Connectland dock, and OS X Yosemite would complain that the disk cannot be read and suggest that I initialize it.

This happens to both Seagate and Toshiba disks.

In both cases, the disk would be recognized as a 3TB disk. I can also use the full capacity of the disk, provided that I put the disk on the dock where it was partitioned and formatted - i.e. if I partitioned and formatted a disk on the Connectland dock, I would have to keep using it on the Connectland dock.

What's going on? How is this even possible? How am I even supposed to shop for a new dock reliably if my dock dies?