Looks like Relics are behind the G13 wall again?

What happens is that if you have a 6* relic 1 character, you can go into the relic amplifier level and upgrade it, but once it's R4 (or R3 for 5* and so on), it just shows you that message. They could change the message to say "this character can no longer be upgraded at the current star level" or something similar.