I did try both Divinity2.exe and Divinity2-debug.exe. They performed the same. I also tried running as administrator. What I didn't try (yes, I feel like a complete idiot for not), was compatibility mode. Running as compatible for Windows 7 appears to have done the trick.
The install path used was the default set by the gog installer: C:\GOG Games\Divinity 2 Developer's Cut. I usually trust the installers to know what they are doing when it comes to placing files.
Renaming the profile folder also had no effect.
However, as mentioned above, setting it compatibility mode for Windows 7 seems to have worked. If it doesn't prove long term stable (more than an hour), then I'll report back.
Thank you for the quick response and the help.