try see if you can activate Grab contactless on Grab app itself
you mean tap and pay function within the grab app, right?
It is rather erratic in the sense whereby sometimes it work (like 49% of the time) and sometimes it don't (like maybe 51% of the time), if I can put a number to the frustrating situation.
And when it don't work, it'll always get stuck in that rotating circle icon and then after like 5-8mins later a funny error message will always appeared "we don't know what is the problem" or something along that line. happened on all 3 phones.
anyway, so my situation is, contactless within grab app doesn't always work for me, and I prefer not to always bring along the physical card to tap on POS.
As for the grab app scan QR code and pay, it doesn't always get accepted at certain places that I frequent eg. giant supermarket. In contrast, google pay scan and pay work. so I thought would be nice to have a single app for everything just using gpay