For those of you who find the problem keeps coming back, it's early days so far but this seems to have worked for me:
NOTE: if you're unsure about editing the registry, skip step 2. Always backup your registry before editing, and if you don't know what I'm talking about,
definitely skip step 2.
1. First follow the instructions hereon how to uninstall OneDrive from Windows 10.
2. Open the Registry Editor and navigate to Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers. Delte any subkey with OneDrive in its name.
3. Go back to the website in step 1 and follow the instructions on how to reinstall OneDrive. Note that if your local OneDrive location is not the Default of C:\Users\username\ then you'll have to redirect it at the relevant point in the installation.
Unfortunately, if you did skip step 2 I don't know how much this will acheive, but at the very least you'll have established whether reinstalling helps.