It's a little bit of a faff but only takes a couple of minutes.
- You need to upload the .fit files to Strava as you normally would (marking them private presents people giving kudos or commenting
- Download each of the .gpx files (Strava has converted the original .fit files)
- Delete the separate Strava rides
- Head to the website above and follow their simple instructions
- Upload the resulting .gpx file to Strava
The only downside is that I had a slight gap between each 'ride' which meant that in order to bridge that gap it's registered my top speed as 120+mph. No KOMs though.