At the end of the European wars, the British Government took advantage of the Holy Roman Empire being preoccupied to the east and seized control of French Indochina.
Cam Ranh Bay, once the main base of the French Far Eastern Fleet, also changed hands and became a principal base for the Royal Navy.
With this premier military port in Asia, the Royal Navy naturally lost interest in another strategic military town, Singapore.
Of course, that was just lip service. The real reason was that the British Government had been a step too slow, and Sumatra had been occupied by the Dutch, while the Malay Peninsula had fallen into the hands of the German Federation controlled by Hanover.
At that time, Britannia was busy clashing with France and Austria; since Hanover and the Netherlands were both staunch allies, the British Government implicitly accepted this fact.