It's unknown to me as to why this happens, but it's started happening a lot lately.
In this scenario, I closed my laptop for the night, and opened it in the morning to see this message on all of my tabs:
The pages don't seem to be snoozed either.
Expected functionality:
This message does not pop up, and if the webpage isn't there anymore, Orion will load it
Version 0.99.132-beta (WebKit 621.1.2.111.4)
Sequoia (15)