The SQA has been a joke since I was at school, and that wasn't yesterday. Massive fuck up with a few grades in H English in 1989 which was only sorted out by my Headmaster threatening to go to the press. In 2019 they lost DS's second paper in one subject, resulting in a D rather than a B - and after admitting their mistake it took unti Feb 2020 to get a new certificate. The Head of Department concerned said that the year before the SQA has lost ALL the Adv H coursework in that subject from our school.
Mind you, with a fuckwit like Swinney in charge, what do you expect? The SQA suffer from typical public service bloat - no accountability, no transparency, lots of nothing public sector jobs developing something or managing something or writing a policy on something. All when they can't get the basics of running sodding exams right.
I said at the time of my DS's mark fiasco that it would be lovely if schools had the freedom to do as schools in other parts of the UK do and choose which exam board to use. A bit of healthy competition in the market might make the SQA up their game if they're competing for "customers" with AQA or Cambridge or whatever.
At the moment they can be completely and utterly incompetent (and frequently are) and there are no consequences to that at all.