there’s a pink box showing time signature information. I don’t know how it got there! Is it important. I have a time signature at the beginning of the piece and I don’t need another one here, but it doesn’t seem to have put an extra one in.
It indicates a barline override or a hidden time signature (which are sort of one-and-the-same). Did you input a normal barline at that position? Try selecting the barline (not the signpost) and pressing Delete.
I found myself with by the exact same problem. Having an ordinary passage of 4/4, an extra time signature chose to appear randomly in the middle of nowhere, and I couldn’t for the life of me understand why it would do so. However, deleting the barline, as suggested by Lillie, solved everything right away. I guess one must have done something questionable earlier on for that to happen.
Signposts are representations of invisible elements in the score. The barlines aren’t invisible so they don’t get deleted when you delete the signpost. I agree that this appears somewhat confusing and it could use some cleaning up for the sake of the user.