SQL not populating email when using RPL

We've found that several of our campaigns have stopped working when populating elements using RPL from SQL. We have tested it and half of the SQL fields will pull through on some campaigns but the rest are showing as null even though when we look at the SQL view there is data in all the fields. 

Several campaigns were working at the beginning of the week but now we have set the send live it won't pull through any information.

Has anyone else had a similar problem or know of something that could have caused this?