Can you link to a thread where the OTA takes the money but no tkt is issued? That is extremely rare since when agents issue tkts they really are not taking your money the airline is.
The issue is the lag time between a confirmation/booking/reservation (all the same) abd ticketing.
Let's make sure I was clear - I have seen the OTA booking charges (x.co.uk) for this RGN fare go through days ago but no charges from NH thus far and no tickets issued.