The "local" is a directory and the ''local-lvm' is a lvm-thin pool by default. The path of the "local" is actually on a lvm volume called pve-root,while the "local-lvm" is on another lvm volume called pve-data. Pve-root and pve-data are on the same volume group called pve. So you have to reduce pve-root first in order to increase pve-data if there's no extra spaces on lvm group pve and SSD. But I don't think it's a good idea because shrinking lvm volume could cause data loss. But if there's extra space left on SSD, you can increase vg pve first, then you can increase lv pve-data. I'm just a user , not a professional.