I see humidity in Manila can often reach over 80%. Operating electronics in that high humidity can often result in damages since they are always heating up and cooling down between uses, what can lead to condensation on internal parts. Apple has a ton of moisture sensors installed in their products, that are just accessible through opening up the device and when they detected moisture inside the device, apple warranty will not pay. This can, but should not happen to your Macbook, especially when humidity was still under 90%.
Sadly repairing water damage is also very difficult, because you can't always tell what parts are all affected.
I don't know how Apple will react if you somehow proof it was just due to humidity.
The only way to find out more is probably to Contact Apple Support.
I hope you find a solution!