minor but irritating anomoly

Occasionally I get situations in my scores where a double time signature appears. It seems random but I can't seem to budge it, even when I try to delete either or both of the time signatures or alternatively try to re-create the bars (with the latter I have tried multiple ways of doing this, but to no avail. It always adds the double time signature back in eventually). Updates have had no effect on the problem either, perhaps because no-one has reported this issue before, I don't know. Bottom line is...I have no idea what causes it. Other bars in the same piece appear as they should, until suddenly quite randomly it does it again. See examples below