It's not a GA code because those are represented in base32 and according to the RFC the base32 alphabet does not include the character 8.
OP made up an example to show what it looks like. It could very well be his original code is 15 characters base32, but he didn't know that when he typed "JPGZE4MATACPN8L" as an example.
lol yeah that's possible. OP can you compare the characters with the character set here: