glad i stumbled on this - had the same problem and i spent the weekend reconfiguring my nas and turning off all updates for now. Igor you have done great work over the years and absolutely understand the difficulty. I wish I knew programming and could assist. However the helios4 has had a great run, its def time for an upgrade.
I had a bunch of random issues - stuttering, freezes, issues while copying. It turned it out the issue was extreme amounts of dust on my unit. I disassembled it, thoroughly cleaned everything out - and that fixed my issue