I downloaded your files and both had the extra sigs.
I removed them and saved. There are 2/4 sigs at 23, 33, 43, 53, 63. Each is followed by a 4/4 sig on the following bar.
I saved, then closed the file. I then reopened and observed no change on the time sig track.
Here is the file after I saved it: https://we.tl/t-vQLbO2TKJa (link expires in 7 days)