Forgive me, I'm extremely rusty on all of this! I just uploaded my Pokemon Red save to PkHex and I saw the red exclamation mark next to both of my Glitch Mew (one from Gambler and one from Jr. Trainer in Cerulean). To check what a legit one looks like, I uploaded the one on here and it also has the red exclamation mark. Just to test, I edited one of my Mews to have one of the 90s distro IDs and OTs, but it still came up with a message: "Unable to match an encounter from origin game". Even the legit Mew from this forum has that flag.
I am going to teach myself how to transfer from Gen I to the current Generation and am curious if that "encounter from origin game" flag will prevent the Pokemon, even the legit one, from being transferred. Or do all Mew in Generation I have that flag and, for Mew, it is something I can ignore?
Any help is greatly appreciated!