Exporting to Windows Document

When I try to export a project to a Microsoft Word Document I am seeing a random removal of spaces between words. Words that are correct in the source document are being concatenated. In some cases its multiple consecutive words for example no running about in the scrivener document becomes norunningabout in word. Exporting to a pdf or rtf gives the correct result of no running about.

I have checked the source document carefully and the published book both of which are correct with no running about.
There are some 20 examples of this issue in the word document where the source document is correct.
Versions
Scrivener Version: 1.9.8.0 - 15 Jun 2018
Word 2016 fully updated.

Is this a known issue or something new?

Thanks
Martyn