I know you’re not the only one with a malfunctioning store app; I’ve already said so. And no one knows why the app malfunctions for you and others, while working well for some.
I did replicate what you described in your links, and I think my post above explained it:
Nobody here is blaming you.
At this point you either have to follow one of the working methods, or take no action at all while you wait. It’s totally up to you.
Actually, there is one more thing you could try in the terminal, and that is:
sudo apt --reinstall install librem5-gnome
which might correct the software app, but no guarantees.
ref: App store "Software" disappeared after pureOS update - #20 by dos