Roon 1.3: problems loading albums

I’ve already reported this problem (as other users did), but I’d like to know if its origin has been identified and if there is a chance to get a fix soon.
For a couple of days now, Roon has become very unstable and very difficult to use. Album loading is extremely slow (or even impossible). Sometimes I get the “Error loading saved paged” message, and in the Albums window, I can only see the 3 or 4 first windows (ABC) showing the album covers. The Force Rescan command (in the Settings>Storage window) for a watched folder doesn’t work.
All these problems occur inconstantly; sometimes, it works (but most of the time it doesn’t).
I’ve tried different things (rescan folders, clearing image cache…), without success.

My Setup:
Core: NAS-QNAP TVS-471 (Intel Core i3 / RAM : 4Gb), with RoonServer is installed on an internal SSD drive (Samsung Pro 850 128 GB) of the NAS and music files (22.400 tracks) stored in the NAS (WD RED Pro Edition, 6TB - 7.200 RPM - 128MB cache).
Router: Asus RT-AC87U AC2400. Other networking hardware: Logitech Squeezebox Touch (connected to the router via Ethernet), Sonos Play 1.

Thanks for your help,
Thierry