In the Boruto: Naruto Next Generations - Episode 136 Crossing Time!, Sasuke uses his Sharingan to erase the memory of both Jiraiya and Naruto since they have learned things they shouldn't which can disrupt the timeline. Since Genjutsu won't affect Jiraiya, how did the Sharingan's ability erase Jiraiya's memory?
How can Sasuke's Sharingan erase Jiraiya's memory?
Tampering with people's memory, although not necessarily with genjutsu, is definitely a thing in Naruto's world: for instance, in Naruto manga chapter 247 Sasori claims to have a few sleeper agents whose memory he had previously concealed; films and anime have used this trope a few times to mantain consistency of fillers with the main storyline. So it isn't surprising to learn that sufficiently powerful genjutsus can erase memories, and we may as well take Jiraya's nonchalant claim that this is possible as an in-world declaration that it is possible.
Since Genjutsu won't affect Jiraiya, how did the Sharingan's ability erase Jiraiya's memory?
The premise is false: it's never been stated that Jiraya is immune to genjutsu.
