Asking for a friend:
On Kiddushin 38a, Tosfos s.v. Tzei, explain that Hashem didn't approach Yehoshua until after the 30 days of mourning for Moshe had elapsed, since the Shechinah does not descend and come unto a person during times of Aveilus, mourning. (Technically speaking, this is based on Berachos 31a, which talks about the Shechinah not coming to someone who is sad; however, Tosfos seem to view it as a connection to the technical Aveilus.)
How would Tosfos explain Sotah 14a, which states that Hashem visited Yitzchak during his period of mourning for his father?