Apple Pay or Google Pay can disappear even when the gateway itself still works. Wallet eligibility is evaluated from the browser, device, merchant/domain registration, HTTPS and the specific gateway configuration. Test those layers separately.
Confirm the shopper is eligible
Use a supported browser/device, a configured wallet and a real product/checkout context. Incognito or unsupported environments can produce a false diagnosis.
Verify domain and merchant registration
Check the exact canonical checkout host, including www/non-www or regional domains, in the gateway/wallet configuration. After migrations, registrations often still point to the old host.
Inspect HTTPS and verification files
TLS must be valid and any required domain-association file must be reachable exactly where the provider expects it, without redirects or authentication.
Check gateway conditions
Currency, country, product type, subscription support or account capability can hide a wallet while card checkout remains available.
Look at the browser console/network
JavaScript errors, blocked scripts or consent/load-order changes can prevent the wallet component from mounting.
If the wallet reaches payment but totals diverge, compare with checkout total vs payment window. For payment evidence, use safe payment tracing.
Build a small wallet test matrix
Record one supported and one unsupported combination for device, browser, country/currency and logged-in state. Repeat after clearing checkout/session state. A matrix prevents “it appears on my phone” from becoming the acceptance criterion and makes later browser or gateway changes easier to diagnose.