License clarification

[cedk]

Hi,

py-xml-escpos has a MIT license shared between Frederic van der Essen and Manuel F. Martinez.
But I found https://github.com/python-escpos/python-escpos which also has Manuel F. Martinez as author but under GPL-3 license. Both projects seem to share a great amount of code and python-escpos is quite older.
So I'm wondering if the MIT license of this project is correct? Should it not be GPL-3 as the author of python-escpos wanted for their code?
It will be great to clarify the situation before being able to use this project.

Thanks.