Created attachment 157704 [details]
Test docx compared in MSO and LO
1. open DOCX from attachment 150186 [details]
2. see that upper text boxes are missing
DOCX is from Office 365 but can be seen in MSO 2013, as in screenshot.
I'll set from LO 4.3. Before, it couldn't be open. Test master 7.0+.
The file can't be open with MSO 2010 claiming there are problems with the content. it seems one of those files with problems among different versions of MSO too
I confirm it with
Version: 18.104.22.168.alpha0+ (x64)
Build ID: eeb2d19e77d6dc47c68e8ba0920a02cf64a1247b
CPU threads: 4; OS: Windows 10.0 Build 18363; UI render: default; VCL: win;
Locale: de-DE (de_DE); UI-Language: en-GB
Word 2016 shows 5 Textboxes and all are missing in LO.
MSO 2010 is not a reference anymore to be certain for all bugs.
In this case, I used 2013 and reproduced if resaved with 2013.
But there may be cases where even 2013 is not enough, if created with 365.