Yeah, Obi-Wan intentionally misled Luke, and it’s addressed.
TRoS presents Luke as spending years searching for Exegol and the Wayfinders. It doesn’t frame it as the Force Ghosts lied to him about where they were, it doesn’t frame it as anything other than a man looked everywhere and asked everyone… except the one person who knew, who he uniquely could communicate with.
It becomes a plot hole because we’re told a character exerted himself, almost desperately, to find something without trying the most basic thing that would also have worked. Like, did Luke get bitter with his father’s redeemed spirit?
Maybe, if it’s not a plot hole, we can at least agree it’s an unnecessarily stupid plot contrivance setting up the videogame-style trading sequence of multiple MacGuffins that we have instead of a story.
Do we have any evidence that Anakin manifested as a force ghost ever again after Endor? Yes we hear his voice on Exegol but that could literally be the first time he’s made contact in that way since ROTJ.
We kind of do! From the (wonderful) reference book “The Secrets of the Jedi”. You can see the page I’m referring to here:
https://twitter.com/AaronQuinton78/status/1159197775562715140/photo/3
The specific part I’m talking about reads: “Their spirits guided me for many years but vanished when I shut myself off from the Force.” So technically no direct confirmation that Anakin physically manifested again, but it feels heavily implied to me.