Issue 7 of Uncanny X-Men: Volume 3 ends with
Illyana teleporting the X-Men out of Limbo into a field somewhere, but she is not with them.
Illyana approaches Doctor Strange,
apparently in the past. She asks for him to train her.
Issue 8 picks up and Illyana is with the team and no mention is made of what happened between these two issues.
I've read all of the issues available on Marvel Unlimited and checked the synopses of the remaining existing issues and there is no indication that these events have been addressed in the Uncanny X-Men issues.
Is there anywhere that explains what happened between Illyana and Dr. Strange during this time frame?