I can assure you this is not a general 7 issue. My Q10 Pro standard daily runs with: SD-Card. Internal HDD and a 4-Slot HDD Bay. All 6 storage devices are detected every time. There are some auto-mount problems though with 7 and maybe they vary with the actual setup?
Check cables and power provision. Specifically USB-3 cables/connectors are notorious for making bad connections.
Please give a much as possible detailed setup with device type/model connected per port specified if you really can reproduce "no problem with 5 and problem with 7" using the exactly same setup.
I think you're wrong because it is WRITTEN ON FORUM FROM FUTEKO that the hdd storage have problem to mounting with new Android 7.
it's written by futeko:
This patch creates persistent mount locations according to UUID and drive label for attached local storage (internal SATA and USB). This location will stay the same on every boot, eliminating the problem where Q5/Q10 Pro can be inconsistent in where it mounts storage (sda1, sda2, sda3 etc) when multiple USB HDDs are attached.
patch v1.0.4
- add DVD/BD-ROM support
- add RUN_ME.bat option not mount/sdcard/media_rw/disk-by-uuid/<uuid>
-
the problem for me is that it takes to patch a Windows-PC
networked with q5 pro. but I have an apple mac-pc and then I returned
the old but reliable 5.1 but with much regret