Most probably, you might have tried to download a post photos as ZIP, but got redirected to the same page with nothing being downloaded, so you needed to try and try again to finally be able to get it. This was an issue with the site code we were aware of. We were implementing a workaround to fix the ZIP download problem these days, and now we introduce that it’s finished and loaded on site.
The new ZIP download method should work on almost any platform and device with no problem. Just give it a try and tell us in comments if anything is wrong.