Email settings: not able to send to multiple recipients

In the past I have been able to set up multiple email recipients for the merchant notifications (e.g. “Merchant: Payment successful”).

However on the last form I set up last week, it appears that it parses the input and removes some of the characters.

So:
When I enter this in the “To Email”: [email protected],[email protected]
Save the form
It shows this: [email protected]

(and obviously the emails do not reach their destination)

Can you help??