Linux Clients - bad transfer after update

Hello,
I updated Urbackup server to 2.5.xx few days ago. Exept windows clients for image backups I have two linux clients for making file backups, and I have problem with them. The clue is before update:

and after:

What should I do to to achieve old transfer speeds?

OK, now I think I know what causing bad transfer - it’s file hashing, or data transfer encryption, BUT,
even with turned off both options transfer isn’t faster than 30MBit/s

Clients working on Intel Atom, and while backuped processor usage is 100%, no less. So my theory is:
Encrytion doesn’t turn off even if turned off in options.

So, after a week not backuping data from that device, I have to ask:

Is it safe to downgrade Urbackup server to wersion 2.4, when I’m having all clients updated to version 2.5.19 or 2.5.20

EDIT:

Backups hit so hard processors beacause urbackup still calculating hashes on client side even if turned off