Mac can't read files saved onto WD Passport from a PC

Hi there - I am hoping someone has a solution to this problem… I recently purchased the 4TB My Passport portable drive in order back up files from another external drive - I have a mac powerbook (running OS Sierra 10.12.6), a previous external drive I was using suddenly was no longer able to mount on any mac computer but was able to mount on a PC. I am trying to back up photos from that previous external drive to my new WD Passport so I can use the files on my powerbook. I formatted the new WD Passport to exFat format as this seemed to be the best way to be able to use the drive between both my PC and my powerbook. The drive mounts fine using either computer, I can open the drives and see the contents using both. However, when I transferred some photos to the Passport via my PC, I can see the files on my mac but cannot open it (error message states that file is not recognized or is corrupted, probably the former as this is a brand new drive and not sure while the few test files I copied would be corrupted). I did get a warning message when I was transferring images via the PC to the Passport that not all of the data/metadata was able to be transferred (not sure what that meant) but it appears that the transferred files are intact .jpg files on the drive, I just can’t open them while using my mac. Has anyone had this problem or have a solution? When I check info on the drive, it looks like the conversion to the exFat format is fine as the drive shows as being in this format. Thanks in advance for any help and suggestions on this!!!