Multicam function (switching cameras) stops working after using graphics

I've had an ongoing problem with the Premiere Pro multicam clips becoming locked (or not working!) after I use the graphics.  To clarify, when I'm breaking down and assembling doucumentary interviews I have a process in which I want to both switch between cameras in the multicam clips - as begin rough cutting - and occasionally add text cards to indicate story beats or where relevant sequences and overlay shots might be added later.  However, I frequently have a problem where, after adding a graphic to the timeline and adjusting the text etc, the multicam function stops working. The only way to work around this (that I've discovered so far) is to quit PP and then come back in to my project before continuing.  This is obviouly an annoying bug and one I've put up with over the last year or so hoping it might be sorted in an update.  That hasn't happened so finally flying a flag about it.