Deztroyer: My friend who just recently leveled up to Master has an avg score of 73.
The different paths of strokeplay vs. "mobile games" have been noted and may contribute to the situation.
It's also noteworthy that a promotion by strokeplay (that is, 67.00 average or lower) will lead to a reset of the average after(!) the next ranked round. Thus, his first Master average would be 67.00 or lower from before, and if your friend scored a 73 at his next round (as a Master), this is his legit new average. It's also normal because the standard tee box has changed for him.
Confusingly, this score may be noted as a "TP" round in the game stats in case of a tournament started as a TP.