This is probably only applicable for a small number of people on the boards, but I knew it would be helpful to others who had gone through the same issue.
When we applied in April, the website did not allow us to pay my son's IHS. We sent in the applications anyway, and phoned up the helpline. They told us to wait for an email from Sheffield requesting it.
We contacted the helpline a month later and were given the same information.
Today, on our 54th business day (!) we finally received the email and were able to pay.
The email states:
Unfortunately there is a bug with the IHS Portal where children appear to be exempt from the IHS payment. This is not correct. We are working to resolve this issue.
The application has been amended for the IHS payment request. The Visa type will appear as ‘Settlement - Parent, Grandparent or Other Dependant Relative’, this is the only way we can continue the process until the bug is fixed.
Please note that if the full payment is not made by 2nd August 2017 then your application will be refused. If this is the only reason for refusing your application, you will have to make a new visa application and your visa fees will not be refunded.
To prevent any further delays with processing your application, once you have made this payment please send an e-mail to ihs.sheffield@fco.gsi.gov.uk containing your name, GWF reference, IHS reference and the amount that you have paid for IHS.
I'm feeling a huge relief!