PayPal Split Payments not accepted

I’ve noticed that starting June 13th several stores powered by Shopify started to refuse split payments from PayPal where it could either be split between 2 cards or part of the purchase is covered by PayPal balance and the rest by the credit/debit card. Before that it was working fine for the same stores/payment methods. Anyone else had the same issue or aware of any changes on Shopify’s end that could cause that?

Thank you so much - really appreciate such a detailed reply, that makes total sense to me! I will forward these to the affected stores and see if they could make changes on their end - cheers!