I think that, with a correctly functioning body, lens and back, it's all down to your routine handling of all aspects of your kit, preparing for an outing, prepared and practiced with each element, marrying them to each other, multiple times and preparing to and actually pressing the shutter, after all that AND measuring/setting the exposure, any filters, lens shade, cable release, tripod mounting and adjustments,
You bought a perpetual but inert, box kit, when you got your Hasselblad and it has to be treated as such, even when lens, filter and film are already all onboard.
Practice handling your kit, listen to music or watch TV or be a passenger on a bus, or just standing on the streetevery day, and you will discover the little quirks of your system, shared or no with other's systems, and handling the box, lens, magazine, lens filter and covers, as well as when and how to meter and execute various settings, will, I believe, reward you with a "process" leading to successful images.
So, you have a couple of choices, if you take the decision to keep this kit; no to practice setting up and shooting, as a Process, or, continue to be vexed by your own unfamiliarity and casual attention to what is needed to make good, photographs with no stress from your kits operations.
IMO.
PS. I am using a Hasselblad 'wrist' strap on this 500 CM, and occasional, I am practicing lens/backs/viewfinder changes/holding it, with the side handle grip or setting up on my tripod with one or all these attachments, so I can avoid a recent unpleasant film changing of a back, being out of practice for many years. Dropping or putting your thumb through a curtain or otherwise damaging your kit by misadventure or even just appearing clumsy in from of someone/people you are/are wanting to photograph, is very bad JuJu, also IMO.