It’s not clear from your log what is causing the issue. It’s also not clear to me which desktop environment you’re using, but I know that neither Gnome Shell and KDE Plasma automatically activate a standby mode timer for HDDs. You have to do that manually (and that’s why I created the AntergosConfigurator script to set that up easily). But what I want to say with this , is that if you didn’t configure a standby mode timer for your HDD, that couldn’t be causing the issue.
With USB things are different though, I think drives do get automatically in standby mode after x amount of inactivity time.
It could be some software or hardware malfunctioning. I recommend for the next step that you try again after physically disconnecting your HDD from your computer. If it still happens, it’s not the HDD