Description:
Disabling keep with next paragraph from styles sidebar -> Modify doesn't apply to document

Steps to Reproduce:
1. Open attachment 179635 [details]
2. Place cursor in the yellow highlighted area
3. Sidebar -> Styles -> Paragraph Styles -> Avantpuce (is selected)
4. Right Click -> Modify
5. Text flow tab -> Un tick Keep with next paragraph and press OK 
6. No change -> bug
7. Right click somewhere in the yellow text -> Paragraph -> Paragraph
8. text flow tab
9. keep with next paragraph -> untick & press OK -> working as expected

Actual Results:
Unchecking Keep with next paragraph doesn't have any effect in document

Expected Results:
Should be the case


Reproducible: Always


User Profile Reset: No



Additional Info:
Version: 7.4.0.0.alpha0+ (x64) / LibreOffice Community
Build ID: 4659fc2f0a7223a89446edff0b77e58758b5edf5
CPU threads: 4; OS: Windows 6.3 Build 9600; UI render: Skia/Raster; VCL: win
Locale: nl-NL (nl_NL); UI: en-US
Calc: CL Jumbo

and in
4.4.7.2

and in
4.1

and in 3.5.7.2