Hi Jason,
Thank you for the question and I am very sorry about the issues!
About the Startup dialog does not show any recent opened files, it is a known issue to us. The update 2 for Archicad 23 should have been fixed this issue. The reason was there is a file called ACRecentList.lck in the Preferences/GRAPHISOFT folder. This blocked the writing of new opened projects to the startup dialog. Also, if you block the access to "Recent Documents (Symbol).prf" and "Recent Documents (Project).prf", this could also prevent AC from adding recent projects.
Regarding the previews in the dialog, I would say that, the previews only show "cache" memory of the project files, not the real content inside it. I believe that AC was unable to create proper preview images for option 2, therefore it still shows up similar to option 1. I suggest reopening option 2 file, play around with it for a bit, and save it. Hopefully it will refresh the cache previews.
Please let me know if it answers your questions. Thank you very much!
Best regards,
Minh
Minh Nguyen
Technical Support Engineer
GRAPHISOFT