Last week returning to T5 eGate tried 3 times then gave 'Seek Assistance' with a long queue for the well staffed BF desks doing manual checks. So 100% failure on UK eGates, no problems with EU ABC where accepted.
Using a ePassport NFR reader the chip works fine but reports 'Passive Authentication failed' whilst 'Chip Authentication Pass'. My OH has an older passport which reports Fail on both so not sure the app is much use. PA is the first step and any failure results in the rejection which would explain the very fast 'Seek Assistance' response.
More interesting is the chip activates a credit card reading app which say my passport is a Visa Debit card expiring in 12/22 with 3 PIN attempts allowed and checking the card number "The credit card number you entered passed the Luhn Check and is therefore a valid credit card number!" and my passport expires in Dec 2030. Card BIN 465922 reveals "VISA debit card (PLATINUM level) issued by Barclays Bank Plc in United Kingdom" and from my time at Barclays I know they use Gemalto card personalisation services as does UKPA (mine is one of the first black passports which use Gemalto NFID chips).