Sales emails are being sent directly to me as well as our customers when they shouldn’t be

Really weird error for us and I can’t see where it could be coming from.

Our sales emails are setup to send to the user and BCC to a number of internal addresses. Since last week it’s been acting off.

If a user pays using card, the sales email reacts as expected.

If a user pays using paypal or bank transfer, the sales email is sent directly to my email address, the customer and then BCC’d to everyone in the list. I’ve removed my email from the BCC and it’s made no difference.

I know no one can say for sure what it is with our store, but has anyone else experienced a similar issue and have any suggestions?