Hi appleZac,
welcome to the Apple (user-to-user) Community.
Re: "Boarding passes or store cards disapearing from wallet"
and
"Can anyone explain what is happening or suggest a fix please? "
Wondering if some passes may have just been "hidden" before time.
Apple Support's article:
Remove passes from Apple Wallet - Apple Support
says
"Some expired passes might be automatically hidden".
and:
"Expired passes
Some limited or single-use passes, such as boarding passes or event tickets, are automatically hidden after they expire. These passes are moved to a separate list, where you can view, unhide, or delete them:
- Unhiding a pass returns it to the main view of the Wallet app.
- Deleting a pass removes it permanently.
How to view, unhide, or delete expired passes on your iPhone:
- In the Wallet app on your iPhone, scroll to the bottom and tap View Expired Passes.
- Tap a pass to view its details.
- Tap Unhide to return the pass to the main view of the Wallet app or tap Delete to remove it.
You can also tap Edit to unhide or delete multiple passes at once.
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For store cards:
Wondering if they could also be "hidden" as above.
or
You might want to check their app or website to see if they provide options for use of their store card with wallet.
Other Apple Support "Wallet" articles:
How to: Keep cards and passes in Wallet on iPhone - Apple Support
How to: Add, use, and share boarding passes, tickets, and other passes in Apple Wallet - Apple Support
All the best :-)