Today, strange...
I was outside with SIMBA, my phone not a 5G phone, so was on 4G/4G+. Tried to top-up MRT Card via SimplyGo app; tried a few times but all kept spooling awaiting for SMS OTP. Finally gave up.
When at home, connected to home WiFi, I tried again & this time no problem ie manage to top-up the Card.
Then I immediately switched off WiFi & with only SIMBA connected I tried to top-up another Card, & the same thing happened like when I was outside. I decided not to top-up via WiFi yet & continue to play2 with SIMBA - still no luck after an hour+.
Previously, I realized now, I've been successfully topping up via my home WiFi & twice when I was in JB via Celcom with SIMBA's Roaming.
So please let me know where I can feedback to SIMBA for improvement.
Thanks.
P/S: So can I receive SMS OTP via solely SIMBA's network? My answer now is no.