I am not (yet) doing some forth and back workflow in darktable but also missed a refresh button for marked images many times, as there are race conditions which often make darktable miss an update after propagating changes by history copy-paste. I did not do a bug report as I do not have a way to reproduce this reliably though.
What I do then is to go to every missed image, open it in darkroom, switch off and on some module and go back to lighttable That’s not the cleanest way as it introduces history changes, but at least it updates the thumbnail. It’s a bit of extra work though, especially as sometimes more than 10 images are missed.