I use Samsung On5 Pro mobile with Android 7.1.1 OS.

I took a few photos using the in-built camera and later saved them to my PC in May 2017. I deleted all these photos from my mobile immediately after saving them to the PC. Today, I copied the same photos back to my mobile using a data cable and sent them to a friend via WhatsApp. But, when I checked the sent images folder within WhatsApp on my mobile, I noticed that the original names of the photos had been changed. The names or titles of these photos when originally taken in May 2017 were a combination of date and time, something I am quite comfortable with, you can call them time stamp if you like, but I accept them as the name or title of the photo as it often gives me a clear about the date and time of the photo when it was taken. So how do I make sure that when I send photo/image via WhatsApp, its original name or title (a time stamp in my case) remains unchanged?

I copied the photos from my PC to a variety of folders on my phone namely Camera, DCIM and Download and sent them via WhatsApp to see whether sending them from a different folder might result in their names/titles being unchanged by WhatsApp's sent images folder, but to no avail.

I have uploaded 2 screen shots at the below URL. This is after connecting my phone to the PC running Fedora 25 Workstation 32 bit.

As you can see, first screen shot (Original photos) shows 5 photos (originally taken in May 2017), which I saved to my phone from my PC today. The second screen shot (WhatsApp Sent Images Folder) shows 15 photos in 3 sets of 5 photos each after saving them to 3 different folders on my phone namely Camera, DCIM and Download as indicated by different color lines.

Thanks a lot.