Symbols from multivariate analysis not visible in legend in Layout

[9ls1]

Describe the bug
Symbols from multivariate analysis not visible in legend in Layout.

How to Reproduce
I have followed the steps for creating proportional symbol and multivariate analysis (QGIS docs). It looks like expected in the canvas and in the Legend Items-window in "Item properties"-tab in the Layout.

However, the symbols are not visible in the legend in the map. How may I make the symbols visible also here?

QGIS and OS versions
QGIS ver. 3.16.0-Hannover on Windows 10, 64 bits.

Additional context
@MrXsquared could reproduce the bahviour 3.14.15, 3.10.11 and 3.4.12 on Win64bit versions.

See https://gis.stackexchange.com/questions/378556/how-to-make-symbols-visible-in-legend-in-layout

[roya0045]

Could not replicate on win 10 QGIS 3.14.16 using either categorised or graduated symbology

[9ls1]

Thanks. OK, so for now, I have to reinstall the previous version of QGIS to get the desired legend.

[roya0045]

Maybe not, can you post your full specs, I have installed through osgeo
QGIS version
3.14.16-Pi
QGIS code revision
df27394
Compiled against Qt
5.11.2
Running against Qt
5.11.2
Compiled against GDAL/OGR
3.0.4
Running against GDAL/OGR
3.0.4
Compiled against GEOS
3.8.1-CAPI-1.13.3
Running against GEOS
3.8.1-CAPI-1.13.3
Compiled against SQLite
3.29.0
Running against SQLite
3.29.0
PostgreSQL Client Version
11.5
SpatiaLite Version
4.3.0
QWT Version
6.1.3
QScintilla2 Version
2.10.8
Compiled against PROJ
6.3.2
Running against PROJ
Rel. 6.3.2, May 1st, 2020
OS Version
Windows 10 (10.0)
Active python plugins
quick_map_services;
timemanager;
db_manager;
processing

It might be something else or just a bad setting that doesn't make them appear. If you could share a sample project it would be easier to see if the issue comes from qgis or if we missed something.

[9ls1]

I have also installed through OSGeo4W.

Here is a small sample of the data set (zipped gpkg-file):
multivariate_analysis_legend.zip

[gioman]

@9ls1 it does not work on 3.16 and also 3.10, in fact this seems duplicate of #32710

[roya0045]

Tested on master on linux, the points are there in the legend, just quite smaller. If you increase the default size of the points, does that changes things?

[gioman]

the points are there in the legend, just quite smaller.

Actually they are invisible, because they are of size 0.

The parameters that must be changed in order to see them is

that by default is "0". Not sure if is by design or not, but does not seems intuitive that this must be changed in order to see the symbols in a legend in the composer.

[roya0045]

Even on the version that I tried, I set it to two but the symbols in the layout were quite smaller than the layer tree and the layout legend item 'preview, since they were present on the issuer's preview I am assuming that the value was set since we could see them.

[9ls1]

@gioman Thanks a lot! That did the trick for me. Here I have set a minimum size of 2.2.
I agree, it doesn't seem too intuitive to set a size when null. Or did I miss something in the docs, hm.

[roya0045]

@gioman should we set a default value of 2 to prevent confusion? It's just adding a default value to

QGIS/src/ui/qgspropertysizeassistantwidget.ui

Line 49 in b3d2619

<widget class="QgsDoubleSpinBox" name="nullSizeSpinBox">

[gioman]

@gioman should we set a default value of 2 to prevent confusion? It's just adding a default value to

@roya0045 ok for me, but the point is... should not the symbols also show even of that option is set to 0?

[roya0045]

The legend is populated from existing symbols, if the reference symbol doesn't have any value to set the size (which should be the case as its a reference symbol) then the size is 0. From what I can understand.