[6.12] UI doesn't allow me to create pool with old name

On 6.11.5 I had a pool created with steini84's plugin with the following configuration:

root@Tower:~# zpool list -v
NAME                                    SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
tank                                   43.6T  31.4T  12.3T        -         -    49%    71%  1.01x    ONLINE  -
  raidz1-0                             43.6T  31.4T  12.3T        -         -    49%  71.9%      -    ONLINE
    ata-ST12000NM001G-2MV103_ZL274PFX  10.9T      -      -        -         -      -      -      -    ONLINE
    ata-ST12000NM001G-2MV103_ZLW0DGSE  10.9T      -      -        -         -      -      -      -    ONLINE
    ata-ST12000NM001G-2MV103_ZLW0DNWE  10.9T      -      -        -         -      -      -      -    ONLINE
    ata-ST12000NM001G-2MV103_ZLW0DQ2G  10.9T      -      -        -         -      -      -      -    ONLINE

I wanted to create the pool in the UI using the same name but I doesn't let me:

I started the array without creating the pool and checked the shares but there is none of that name