Uppy not accepting certain email subjects\filenames with colons

Hi, when uploading ‘msg’ files into our web app (by dragging and dropping them from Outlook) it works 99% of the time, but occasionally Uppy does not like something and just ignores the file, it does not display an error message, and there is no message in the console.

This subject\filename does not work:
RE: FAO: Chris Wilson re: Auto Cars Wimbledon branch C-101005

But removing the colons, it does work:
RE FAO Chris Wilson re Auto Cars Wimbledon branch C-101005

Additionally, when a email has a single colon within the subject, it works correctly, and Uppy automatically changes the colon to an underscore, is there away to get Uppy to do this for all colons?

I thought it was something I may have done, but this also fails on the Uppy examples page.

Thanks, Chris