WI / AHC: Ramathipadi I / Sultan Ibrahim of Cambodia isn't overthrown

Ramathipadi I is notably the only king of Cambodia in its history to convert to Islam, renaming himself to Sultan Ibrahim. He did this after being implored by his partner (and eventual wife and queen), Neak Moneang, who was of Cham and / or Malay blood. The two had a daughter, Princess Dav Kshatriyi, and reportedly three sons.

Buddhism was quite entrenched within Cambodia at this time, and so, Ibrahim's conversion made him unpopular among his subjects. He further invoked their ire by replacing Khmer Buddhist officials with Muslim Malays and Chams. Eventually, in 1658, after the Siamese had briefly contemplated invasion, the Vietnamese decided to go through with it, invading upon the request of Ibrahim's two brothers (who had fled from Cambodia to Vietnam), and deposing him. He died shortly after, either killed by the Vietnamese or dying on the way back after being released (we're not entirely sure which of the two outcomes happened).

What could have happened to prevent Ibrahim from being overthrown? I've thought of things like a weaker Vietnam, a greater presence of Islam in the Mekong Delta, the death of his two brothers before they reached Vietnam and Ibrahim deciding not to systematically discriminate his Buddhist subjects (for starters, he doesn't remove the Buddhists from his government), but would like to hear some other ideas too. I'm seeking to not only let Ibrahim keep his throne, but also secure the throne for his successors. Given how Buddhism is an integral part of Cambodian society, how difficult would it be to prevent Ibrahim's descendants from being overthrown? And is there any way for conversions to start happening from top to bottom, as in maritime Southeast Asia?

I decided to make this double as an AHC too. Bonus points if Cambodia becomes a Muslim-majority nation (at least 50-60%) and if it is still ruled by Muslim kings to the present day.
 
Maybe the Cham lands would be annexed by Cambodia rather than Vietnam? Especially if the Cham themselves seek the protection of the Cambodian crown against their northern neighbour. The disputes between Cambodia and Thailand would gain a religious component to them, and since there's a Muslim minority in Thailand to this day, well...
 
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