I got Grab to MNL airport on 31/Mar/2024 and was not charged a foreign transaction fee when using a foreign credit card
Hmm I'll be going again in Jan of next year so I will be on the look out.. but I never had issues with Grab so far.. Only the issue of adding my Chase card while here, I had to try like 20 times before it finally took the info, it kept saying to contact them and it was a invalid card.