Thundurus bug?

When I go to battle thundurus and it uses any buffs (or is debuffed) nothing appears on screen to reflect the change. Same thing happens when I inflict a status on it (no marker pops up indicating that it really is statused).

Any chance that going through all the steps to get it to show up, but then leaving the safari zone caused this? I’m trying to shiny hunt it and am not sure if these visual bugs/glitches would also affect the shiny star from showing up as well