Description:
If you have some headers styles (for example, header 1, header 2, header 3) and click the "Set outline list style"-button, and then decide you want to remove the numbering style, the indentations of header styles 2 and 3 are all wrong, or they are at least not restored to what they were. Neither do they seem to be easily restored manually.

You can later change settings in the "More options" part of the "Set outline list style" and the header indentations will change, even if they no longer should be treated as numbered list items. Changing the styles themselves does not work/seem to help.

You have to create a whole new document to fix it.

Steps to Reproduce:
1. Add some headers (styles) to the text file. For example, header 1, header 2, header 3.

2. Click the "Set outline list style"-button with the "Numeric with all sublevels"-option.

3. Remove numbered headers by either clicking toggling with F12, clicking the "Toggle numbered list" or deleting the area right before the header(s).

Visual example:
* Add some headers to text file *

Header 1
Header 2
Header 3

* Set outline list style *

1. Header 1
1.1 Header 2
1.1.1 Header 3

* Remove outline list style by either manually remove space before header or remove/delete content before the headers *

EXPECTED    |    ACTUAL
Header 1    |    Header 1
Header 2    |        Header 2
Header 3    |            Header 3

Actual Results:
Indentations are not restored for the headers of style 2 and 3. They also seem to STILL be treated as numbered items/list.

Actual result:
Header 1
    Header 2
        Header 3

Expected Results:
Numbers removed and indentations removed.

Expected result:
Header 1
Header 2
Header 3


Reproducible: Always


User Profile Reset: Yes



Additional Info:
Version: 6.3.5.2
Build ID: 6.3.5.2-1.fc31
CPU threads: 8; OS: Linux 5.5; UI render: default; VCL: gtk3; 
Locale: en-GB (en_GB.UTF-8); UI-Language: en-US
Calc: threaded