What does zpool import yield without any arguments?
We had a similar issue a few days ago, unfortunately OP didn’t report back if it worked. It’s weird that the pool is shown in the GUI.
Do you see the disks under Storage / Disks?
Edit: if the disks show up as members of an exported pool you should try exporting and importing the pool again.
Here’s the mentioned thread.
@Protopia suggested exporting the pool in the GUI and then try Importing it again in their last response. I feel this would be the next logical step.