different temprorary images treated as same in officeR or flextable

I have a shiny app that asks user to upload two or more images (different button for each one)
then a docx is generated via officeR with or without the use of flextable

when the document is finally downloaded, the images are the same (the first one).

All I know is that a temp file is created for each image, different folder but all are named 0.jpg
This doesn't happen if locally stored files are called

How is shiny or officer handling this images?
How do I tell it that those are different?

Thank you