Scaling Issue with Printer

[sptnk021]

I'm not sure where to turn to on this, but I just had an issue where I sent art to a printer, for a large scale print at 98in. wide x 112in high.  To reduce the file size, I work in full scale but at 72dpi.  My printer sent proofs back and all of my images were 50% of the size I originally sent.  They tell me that's how the images came to them, via the WeTransfer link I sent them.  I checked all of my files and they were all set to the size I specified, so I'm not sure why they had images at a smaller scale.

I've generally trusted computers to open and save files as I've set them so I haven't always had file names with final sizes as part of the name, but obviously I'm going to have to be extra diligent!  But what could be the issue here?  Is it the dpi? The program itself (currently Adobe CC 2017 Photoshop and Illustrator)?  They program the printer uses for prepress (not sure about that, and the printer isn't even sure why the files came in at half scale)?

[Nancy OShea]

Which applications?

Which print presets?

When preparing files for print, I rarely go below 300 dpi.  If unsure, ask your print professional.  They'll tell you what they need.  It removes a lot of guesswork.