only get the electrum sv from the proper website https://electrumsv.io/ and then learn how to check you're downloading the file, by checking the hash posted by the developer on github
Which is why i am officially offering to help @1785 to find remedy, but frankly, the best advice i have is to get a separate little raspi computer in which to use only for bitcoin sending, which costs about one hardware wallet anyway.
the problem in this regard is precisely that Roger Taylor isn't getting paid enough (at all lol) to handhold users who can't be arsed to learn something of their own accord.
whom I appreciate for his work, especially working on a 'community' project, with no aim for profit in sight, on BSV, which shits on 'community' all day.