Unable to Cancel or delete Invoice lines on inclomplete AP Invoices

We are no longer able to cancle or delete Accounts Payables incomplete invoices in PROD for the last 2 weeks and get error message " This invoice action isn't applicable for the invoice line in its current state'

1. We were previously able to do this but something seems to have changed. Can you advise

2. We are also unable to create more than 16 invoice lines which we were able to before.

Regards
Mercy