It doesn’t appear so thought I haven’t tapped in since. There is no transaction on my credit card account and my balance according to the app is still £20.35 which shouldn’t have triggered an auto top-up. I last used the card on Thursday and my journey history shows:
Start balance £19.35
Auto top up collected £10.00 [this transaction was successfully debited from my card previously]
Hertford North —> Kingston £4.45
Kingston —> Hertford North £4.55
Spent £9.00 [which gives a balance of £20.35]
I shan’t be travelling now until Wednesday so let’s see what happens.