Six months of Apple Pay Suica has worked great for me but a few Japanese users have recently tweeted that Suica screen notifications sometimes stop working with iOS 10.3.1 and 10.3.2. I encountered the issue recently but the fix is simple.
First of all despite all appearances, Suica keeps working just fine for transit and purchases. It’s just that Apple Pay Suica sound and screen notifications stop working. The Suica balance on the screen does not update after Apple Pay Suica recharging or store purchases. Don’t worry, Suica really is working fine, it’s just a notification thing. The fix is easy.
Restart iPhone. Open Wallet and go to the Suica preferences section that you use to recharge Suica. Scroll down and tap: Turn On Service Mode (ヘルプモードをオンにする).
This brings up Touch ID / Face ID verification. Do that and the screen confirms that Suica Service Mode is on. That’s it. After a few seconds Suica Apple Pay notifications will be working fine with the correct balance and all transactions properly displayed.
Suica Service Mode puts Apple Pay in card emulation mode, a one minute mode designed to help you if Suica is unresponsive and the station gate does not let you through. After turning it on there’s nothing more you need to do, after one minute Apple Pay automatically reverts to normal operating mode. Apple Watch users can put Suica into Service Mode by brining up Suica in Wallet then tap and hold until the Service Mode pops up.
3/1/2019: iOS 12.3 and later fixes this problem for most users. If you run into it use the Service Mode fix explained above.