Organize columns not working if the table is empty

[SrNetoChan]

Describe the bug

While preparing a couple of layers for final users, I was using Organize columns to change the order of some fields and hide some other. Some layers it didn't seem to work, no matter what I did. I realized then that it only happens on empty layers. If I add a row, all my configuration would show up immediately. But, if I remove all rows, the problem appears again.

How to Reproduce

1. Create a new table, a scratch layer will do.
2. Add a few columns, 3 or 4
3. Open the attribute table
4. Rigth-click one of the columns and open the organize columns
5. Change the order of the columns and hide some
6. Notice that the changes does not seem to be applied except for the number of columns showing
7. Add a feature. Notice that the order is fixed
8. remove all feature. Notice that the order goes back to the unsorted one.

QGIS and OS versions

QGIS version	3.10.9-A Coruña	QGIS code revision	bf47e9d
Compiled against Qt	5.9.5	Running against Qt	5.9.5
Compiled against GDAL/OGR	2.2.3	Running against GDAL/OGR	2.2.3
Compiled against GEOS	3.6.2-CAPI-1.10.2	Running against GEOS	3.7.1-CAPI-1.11.1 27a5e771
Compiled against SQLite	3.22.0	Running against SQLite	3.22.0
PostgreSQL Client Version	10.12 (Ubuntu 10.12-0ubuntu0.18.04.1)	SpatiaLite Version	4.3.0a
QWT Version	6.1.3	QScintilla2 Version	2.10.2
PROJ.4 Version	493
OS Version	Ubuntu 18.04.5 LTS
Active python plugins	Mergin; socarto_recart_tools; db_manager; processing

Additional context

[SrNetoChan]

Also confirmed in master:

QGIS version	3.15.0-Master	QGIS code revision	014de96
Compiled against Qt	5.9.5	Running against Qt	5.9.5
Compiled against GDAL/OGR	2.2.3	Running against GDAL/OGR	2.2.3
Compiled against GEOS	3.7.1-CAPI-1.11.1	Running against GEOS	3.7.1-CAPI-1.11.1 27a5e771
Compiled against SQLite	3.22.0	Running against SQLite	3.22.0
PostgreSQL Client Version	12.4 (Ubuntu 12.4-1.pgdg18.04+1)	SpatiaLite Version	4.3.0a
QWT Version	6.1.3	QScintilla2 Version	2.10.2
PROJ.4 Version	493
OS Version	Ubuntu 18.04.5 LTS
Active python plugins	Mergin; socarto_recart_tools; processing; db_manager

[troopa81]

This issue had already been reported but I fail to find it.

This is a Qt issue, I created a ticket in january 2019 but as you can see, there is not a lot of activity...

[SrNetoChan]

This issue had already been reported but I fail to find it.

This is a Qt issue, I created a ticket in january 2019 but as you can see, there is not a lot of activity...

Maybe it was closed for being a upstream problem.

[troopa81]

Maybe it was closed for being a upstream problem

The QGIS issue was closed indeed. But even in closed ticket I can't find it.

[troopa81]

I close the ticket because it's an upstream problem