Controller can't connect to LMS 7.9.1

Hi,

since I upgraded LMS to 7.9.1 (on a Synology NAS), the Controller can't connect to the LMS.
The wifi OK, but when try to connect it to the NAS, always drop back a "Can't connect - try again" on the display. So the Controller can't see the Music library on the NAS.

LMS info: Logitech Media Server Version: 7.9.1 - 1504317335
Server HTTP Port Number: 9000
Operating system: Synology DiskStation - EN - utf8
Platform Architecture: x86_64-linux
Perl Version: 5.24.0 - x86_64-linux
Audio::Scan: 0.95
Database Version: DBD::SQLite 1.34_01 (sqlite 3.7.7.1)
Total Players Recognized: 1

The strange is what on the LMS web GUI i can see the Controller, there is on the player list, and there is the informations about it:
Player Model: Controller
Player Type: controller
Firmware: 7.7.3-r16662
Player IP Address: 192.168.1.70
Player MAC Address: 00:04:20:1a:xx:xx
Wireless Signal Strength: 56%

But the Controller stay offline, disconnected from LMS.

I tried it with 2 Controller, on two different LAN (office and home), the effect same: the controller unusable with LMS 7.9 :(
The Controller not show firmware update on own GUI, it seems up to date.

How can I solve this problem, and use the Controller with LMS 7.9?

Thank you!