HMRC Statements missing interim payments due for 2019

Hi

We're currently running through our clients, attempting to reconcile HMRC online balances.

In a number of cases, the online account is not showing payments on account as payable. A telephone call to HMRC does get these reinstated, provided the HMRC officer is reasonably on the ball.

We had a similar issue last year. Have others had a similar experience? I just want to make sure that we aren't doing something wrong here, or if there's any way of getting this corrected, short of numerous telephone calls.

Thanks.

Neil.