[Offline] Inconsistent Behaviour with Test Card Taps in the UK

[renatoniro]

Summary

• When attempting to collect a payment offline with the Wisepad 3 in the UK (GBP currency, UK connected account) - there is inconsistent behaviour when attempting to tap a stripe test card.
  • The Reader will sometimes result in displaying "try card again", then instructing you to insert your card. Payment then succeeds after following the insert flow ✅
  • Other times, the reader briefly shows "insert card", but then payment is immediately cancelled and we observe a 3010 Reader Busy error.

We suspect that this could maybe be due to SCA in EEA such as the UK?

https://github.com/stripe/stripe-terminal-ios/assets/10636415/4120cf2c-115c-43e7-b265-9453d5580038

• Tested the same workflow in Canada (for comparison) with offline tap and it works as expected (presumably as there are no SCA implications that seem to hinder this).

Steps to reproduce

• Run the Stripe Terminal Example App
• Connect to a Wisepad 3 with a UK Terminal Location
• Collect a payment in GBP with forceOffline (against a UK connected account)
• Add tip (if desired) on reader -> Accept
• Tap Card
• See inconsistency (sometimes)

(Anecdotally, it seems like it is easier to notice the Reader Busy case on an offline charge if you have just switched terminal locations when first connecting the reader).

iOS version

16.6.1

Installation method

• Example App

SDK version

• 3.3.1

Other information

• Have seen this intermittent behaviour with both tipping ON and OFF
• We're unclear if this is just a behaviour that happens only in the stripe test environment
• From what I can find on SCA via Stripe Documentation here and here, it alludes that EEA requires pin entry, so would it make more sense for the reader to Always prompt you to insert the card (when offline) to avoid this in these cases?