As usual, I tried to get on the train using Apple Pay Suica at the ticket gate, but it didn’t respond at all and I got stuck. At first I thought it was because I was wearing a thick coat, so I held it up again, but there was no response … When I checked the Wallet app, all the credit cards and Suica were gone.
It sounds like he was using Suica on Apple Watch. Sakakura goes on to helpfully explain what can cause this and how to get your Wallet cards back. The most common cause for a lost Wallet is signing out of Apple ID. Another cause is turning off the passcode. As he points out, the notification warning when signing out of Apple ID or turning off the passcode is vague, it doesn’t specially say you are about wipe your credit cards and Suica from iPhone. Some users are not fully aware of the consequences and proceed, only to be rudely surprised when they find Wallet is empty.
In all cases it is easy to restore a lost Wallet. Sign-in to Apple ID, set a passcode, go to Wallet, tap + , tap Previous Card and re-add the listed cards. Suica is easier to re-add as there are no terms and conditions or security code steps involved. As always make sure iPhone has a robust network connection when adding Wallet cards.
Another issue to be aware of with Suica and PASMO is Express Mode deactivation without realizing it. This happens when iPhone Face ID has 5 false reads (easy to do when wearing a face mask), when Apple Watch is off the wrist, or when the iPhone side buttons are inadvertently pressed in a snug fitting pocket (often aggravated by the phone case).
One oddity I have encountered using Apple Pay Suica on Apple Watch is wrist band fit. Apple Pay Suica on Apple Watch works fine at the transit gate under layers of winter cloths but Express Transit is sometimes deactivated with a looser fitting band. I like wearing the braided sports loop but it tends to stretch over time and become loose compared with the snug fitting solo loop. On a recent trip I had to constantly enter the Apple Watch passcode as my winter coat sleeve layers pulled the loose fitting braided sport loop enough to fool wrist detection. From here on I’m sticking with cheaper, more reliable solo loop which never has this problem.
Here are some guides dealing with re-adding Suica and PASMO: