Hi Brian
I changed over from 10.37R build 81 in the middle of June to 10.37S build 53 using the full update and I am now on build 56 the problem has been there since I changed over in June, i.e. June2017.htm, July2017.htm, August2017.htm all had the last day of month webcam image in all days at end of the month, I have manually corrected these so only the September2017.htm is giving the problem.
I was late changing over so I do not know if it was doing it in earlier versions sorry.
hope this is of some help
Harold