Thanks for reporting this Salvatore! Are you aware of what plans upstream has?
The Jira MDEV-25068 was fixed in Galera 26.4.12 (https://releases.galeracluster.com/galera-4.12/release-notes-galera-26.4.12.txt) in 2022. i don't see any commits on https://github.com/codership/galera/commits/3.x since 2022. i will keep an eye for new upstream releases. I can also review/merge for all Debian and Ubuntu releases still in maintenance a patch if somebody wants to submit a Debian-specific fix at https://salsa.debian.org/mariadb-team/galera-3/-/merge_requests. On a quick look I did not find the 26.4.12 fix (https://github.com/search?q=repo%3Acodership%2Fgalera+MDEV-25068&type=commits) so I am not aware of any specific commit nor if it can be backported to 25.3.37