Change 9 holes mid round

Hello,

I played at a 36 hole course and set up the correct 9s at the start of the round. After the front 9 the starter directed us to a different 9. I saved the full 18 as one 9 and started the second 9 as a stand alone 9. On the web app, the second half of my initial round is blank with only the front 9 recorded. Is there a way to edit and combine rounds? If not, is there a way to change the back 9 if the holes change mid round? Thanks for the help.