SD-filesystem mmcblk0p3 not showing up in Storage-Filesystems

Hi there,
just installed your image OMV_3_0_88_RaspberryPi_2_3_4.9.41.img on my RPi 3. Startup works fine, except "Storage - Filesystems" shows only ...0p1 and ...0p2, but not 0p3. Clicking "Create" presents an empty drive-list. I went on the Rpi as root and submitted fdisk -l, which shows all 3 filesystems on the 16GB-SD-card. System is freshly installed and nearly unconfigured. What am i doing wrong?
Thx and regards