OSMC Trasmission Gui Problem

Hello everyone,
I recently replaced my Pi3 raspberry with a Raspberry PI3 + this is my configuration:
Starting Kodi (17.6). Platform: Linux ARM (Thumb) 32-bit
Using Release Kodi x32 build (version for Raspberry Pi)
Kodi compiled Jun 7 2018 by GCC 6.3.0 for Linux ARM (Thumb) 32-bit version 4.9.30 (264478).
I have enabled transmission with download folder in a smb hard disk on my fritzbox router.
The problem is that when I log in from gui trasmission it is very slow and after the first inputs it goes intermittently and sometimes freeze system and I can no longer access the transmission and I receive connection time out message.
some ideas … thanks