In September 2017, the Sultan of Johor announced that henceforth he and his wife would be styled Majesty, previously they had used the style of Royal Highness in English.

All other rulers of Malaysian states (and their spouses) except the one selected to be King continue to use the style of HRH in English, so one can interpret that they didn't approve of or feel necessary to follow the Sultan of Johor's decision.

I am trying to understand the Sultan's decision. It is near impossible to find anything online. If anyone knows anything, please do share, it would be appreciated.