Thought I'd posted this yesterday, no sign, so trying again.
Bought Obsidian edition from GOG a few days ago, installed yesterday. Install went okay, but options for Trial of Iron and Expert mode are both ON and can't be turned off. Closed and restarted, no change. Rebooted, no change. Thought it might be Razer Cortex messing things up; turned that off, no change. Do NOT want to reinstall - 50 gigs of upping and downing with no guarantee of success. Right now thinking refund, but if there's a fix I'd love to hear of it. There are postings from two YEARS ago with this problem on other platforms, and no sign of a solution. If it helps, possible relevant hardware spec is:
Windows 10 Pro
AMD Ryzen 7 2700X
Sapphire Radeon Ntro+ RX 590
Razer Deathadder Elite Mouse, with Razer Cortex installed
ASUS Prime X470-Pro mobo
Any assistance gratfully accepted!