Just to say, we’ve noticed the same problem. At first I thought it might be a problem with the non-Roman font we’re using for Back Translation into the national language, but when I looked at an English BT using Times New Roman I see the same problem. It is present in 75 as well.
When you start typing after a tick box, the cursor at first starts out tight up against the box. But normally when you stop typing, PT inserts some space after the tick box to separate it from the text. But if it’s the first box of the chapter the space is inserted after the first letter typed rather than after the box. If Iver+Larsen is sending a Problem Report I won’t send another one, but just wanted to say it seems to be a general bug, not specific to any one project.