MariaDB 10.6.x slower mysqldump etc.

Hi,
We have over 2000 databases (innodb)

In April 2022 we moved from #server 1 to #server 2 (which is few times faster than #server1) and we have some troubles:

1. On #server1 there was mariadb 10.4.x and any backups/upgrades were creating really fast (30-60 seconds)

2. We uploaded backups to #server2 but installed there MariaDB 10.6.7 and.... dumping databases is taking ~60-70 minutes + after for example do command on SSH like "service mariadb restart" is making some crash recovery etc.... which is taking 1-2 hours also.... on #server1 with mariadb 10.4.x there wasn't any problems like that, I could restart mariadb anytime and there wasn't any problems...

3. Today (20.08.2022) I logged to #server1 and thinking "hmmm maybe i'll upgrade mariadb 10.4.x to 10.6.x to check if anything will happened like in #server2" - and what? If there were mariadb 10.4.x mysqldump make dumps in 30-60seconds (2100 databases).... after successfully upgrade to mariadb 10.6.x, I tried to reinstall mariadb from 10.6.9 to 10.6.9 (to check how fast is mysqldump) and that stupid mariadb 10.6.9 is doing mysqldump like 1 database every 2 seconds...so 2100 databases give us 60-70 minutes - why it's so much slower than 10.4.x? What should I do? It's terrible problem for us and I don't know how to fix that.... I'm also scared to upgrade mariadb 10.6.7 to 10.6.9 on #server2 (production server) because of recovery crashes after restart etc.

Any ideas??