Have been having issues with disks being unresponsive and dropping off the system, I’m wondering if I might be overwhelming the powered USB hub I’m using. I have 5 USB 3.0 portable HDDs running off it, plus 1 powered one.
This is the hub I’m using. https://www.rapidpcs.co.uk/store/99/product/2990/
You would need to lookup the specs for the drives to find max current draw and add them up. You would then need to look at the PSU connected to the hub to see how much current it is rated for. Since the hub is relatively low cost I would downrate it assuming it can supply stable voltage at 75% of its rated current capacity. If there is much of a disparity between the two then you might consider an upgrade to some aspect of your setup.
It is also worth keeping in mind that compact switching power supplies on the less premium end of the market frequently fail in a manner where they slowly degrade rather than just stop working altogether. This can cause the devices connected to them to have lockups or random instability.