tei/tei/TEI-Portu-WhatsApp.xml is not linked to tei/tei/TEI-Portu-WhatsApp.rnc; it's linked to tei_all.rng and to sampleODD.rng.
tei/tei/TEI-Portu-WhatsApp.xml is not valid against tei/tei/TEI-Portu-WhatsApp.rnc.
tei/tei/TEI-Portu-WhatsApp.xml is valid against sampleODD.rng.
It isn't clear (well, to me) what roles these different schemas serve in the project, but I think what you want to do is:
Delete tei/tei/TEI-Portu-WhatsApp.rnc.
Rename sampleODD.rng (and also the ODD file from which is was generated) to something like TEI-Portu-WhatsApp.rng (and .odd), so that the file names will be make sense.
Remove the association between the XML and tei_all.rng, since that doesn't seem to be contributing anything to the validation.
There seem to be some related schema issues:
It isn't clear (well, to me) what roles these different schemas serve in the project, but I think what you want to do is: