My reservations window isn’t open yet, so all of my suggestions are really only based on other posters. I’m sorry they haven’t helped for you.
I saw @robin_brown_664876’s post below which suggests that it may help to change countries on your profile page if that isn’t something you have tried yet.
I get that it is really rough when IT screws up and you have to try over and over. I hope it works out for you.
ETA: Sorry, just noticed that you were on that thread, so probably already something you’ve seen…