This is not just for Insider Preview builds, but occurs every time a new public build is installed. I have had to reinstall Speccy four times already this year. I have Windows 10 Pro, and I keep waiting for them to create a Group Policy to change this behavior but so far it hasn't happened. It's super annoying. Speccy runs perfectly, so Microsoft needs to whitelist it. Have the devs made inquiries about this?
I can confirm Speccy is still misreporting this card as having 2048 MB in v1.29.714. The device ID, subvendor, and revision are all being read correctly. Windows 10 reports 6144 MB in Display Adapter Properties.