Fail to start SDDM from a BTRFS snapshot in GRUB

Hi all :raised_hand_with_fingers_splayed:

I just did a fresh install of Manjaro KDE using BTRFS partitioning, using the manjaro installer.
I have installed also snapper snap-pac-grub snap-pac grub-btrfs to automatically take system snapshots and be able to boot on them from the Grub menu.
I have the following volume structure provided by the command sudo btrfs subvolume list /

ID 256 gen 7542 top level 5 path @
ID 257 gen 7542 top level 5 path @home
ID 343 gen 7527 top level 256 path .snapshots
ID 344 gen 5110 top level 343 path .snapshots/1/snapshot
ID 383 gen 6084 top level 343 path .snapshots/40/snapshot
ID 393 gen 6977 top level 343 path .snapshots/49/snapshot
ID 407 gen 7233 top level 343 path .snapshots/63/snapshot
ID 408 gen 7235 top level 343 path .snapshots/64/snapshot
ID 409 gen 7245 top level 343 path .snapshots/65/snapshot
ID 410 gen 7247 top level 343 path .snapshots/66/snapshot
ID 411 gen 7255 top level 343 path .snapshots/67/snapshot
ID 412 gen 7256 top level 343 path .snapshots/68/snapshot
ID 415 gen 7321 top level 343 path .snapshots/71/snapshot
ID 416 gen 7324 top level 343 path .snapshots/72/snapshot
ID 417 gen 7334 top level 343 path .snapshots/73/snapshot
ID 418 gen 7336 top level 343 path .snapshots/74/snapshot
ID 421 gen 7458 top level 343 path .snapshots/77/snapshot
ID 422 gen 7469 top level 343 path .snapshots/78/snapshot
ID 423 gen 7523 top level 343 path .snapshots/79/snapshot
ID 424 gen 7524 top level 343 path .snapshots/80/snapshot

I do have my snapshots listed on the Grub menu. However, when I try to boot from one of them, I get the following error :

[FAILED] Failed to start Simple Desktop Display Manager

I am struggling to find relevant information on the system journal.
I have many The X11 connection broke (error 1). Did the X11 server die?. But, is it connected ?

Has anyone seen that ? Would you have an idea on how to troubleshoot that ?

Thanks! :pray: