Trouble consistently scanning external drives

When using GParted from booting a Live CD I have four external hard drives, to which I make backup copies of my internal disk partitions, attached via USB3 to an IcyDock station. Gparted does pick up the external drives but is wildly inconsistent in scanning the partitions on those drives. I often have to close and open the GParted program a number of times, or instruct GParted when it is open to Refresh a number of times, before the partitons are scanned correctly. With the partitions on my two internal hard drives there is no such problem scanning correctly. I can see the lights on my IcyDock station showing that all four of my external drives are on and functioning correctly, so I do not think it is a hardware problem on their part.

While I appreciate that the latest release of GParted has greatly speeded up the time to scan drive partitions from the much slower times of the past releases, it does seem in my case that this speedup has greatly reduced the accuracy of the scan. Eventually GParted does pick up the partitions on all my external drives correctly, but this is now at the price of often having to do the scanning multiple times to get the correct result.