This was posted some time ago but I'm running into the same issue. My A/B test has been running for quite some time, I have decent visit and conversion data, and I'm utilizing the "Auto-target for personalized experiences (50/50 split)" traffic allocation. When looking at reports I'm seeing green checkmarks so the algorithm models have been created.
Automated segments and Important attributes reports are showing an error message when trying to pull up even though I have the report dates as either 15, 30, or 45 days. Error message reads "Automated Segments and Important Attributes not available for this date range". Any solutions to this problem?