The first stop for Apple Pay Suica Troubleshooting is the English language JR East Suica Apple Pay support page. Common issues are covered there, my pages below cover them in more detail especially when using Suica App to resolve recharge issues.
Troubleshooting Apple Pay Suica #1 Suica registration problems
Troubleshooting Apple Pay Suica #2 Suica C102 Errors
Lost iPhone and Recovering Apple Pay Suica Recover Suica from a lost or stolen device
Migrate Suica to a new iPhone Move Suica to a new device
Renew Suica Commuter Plan How to renew Suica Commuter Plan after expiration
iPhone X Suica Problem iOS 11 bug causes occasional read errors with iPhone X
Fixing the Suica Lockout JR East locks Suica after 6 months of inactivity but is easy to fix