Filenames upset my Browser

I put on a web page a set of photographs with names  base_name001T.jpg...to base_name015T.jpg

The browser (Google Chrome) gave a perfect rendering of the page when it was in my computer, but when I put it on my website the files base_name009T.jpg and base_name011T.jpg  were not found, and base_name010T.jpg was converted to base_name001T.jpg. There was no problem with the other files.

I doubt if there was an error in copying the files to the site as I use a batch file to load all the jpg files in the relevant directory. Nevertheless I checked that the errant files were on the site and in the correct place, and reloaded them several times with no effect.

When I entered directorypath/base_name010T.jpg into the navigation bar of my browser, the file name was altered to base_name001T.jpg and that file then displayed.

Eventually I renamed the problem files base_nameZ09T.jpg,
 base_nameZ10T.jpg, base_nameZ11T.jpg, and then all was well. I wonder what happened ? Why just those filenames, and not the others?