No blocking reason selection possible for automatic release

What causes this issue?

You have selected <LS>Select blocking reasons</> and <LS>Release
automatically</>. This is not possible.
Invoices can only be automatically released if the reason for blocking
is no longer valid. This applies to qnty, price and schedule variances
only. The system checks the blocking reasons automatically; therefore it
is not possible to select the blocking reasons.

How to fix this error?

Do you want to release the invoice(s) automatically?
No --> delete the <LS>X</> against <LS>Release automatically</>.
Yes --> delete the <LS>X</> against <LS>Select blocking reasons</>.

Error message extract from SAP system. Copyright SAP SE.