It is known that Tanzania does not take English seriously. Their education system is centred around Swahili with English simply being taught as one of the subjects.
For Primary school students, all other subjects are taught in Swahili, and it is only in Secondary that they really start studying the queen’s language. Perhaps that explains why their influence in Africa is not really felt.
It happens that even their Universities leave a lot to be desired. These screenshots show the Twitter handle of Mzumbe University.