How to show current setting of group Item

Hi all,
I am using Groups to set the brightness of groups of Hue lights. I frequently use the android app on a small screen and the slider is difficult for my large fingers ;-). So I like to use ‘Selection’ and map a few discrete values to the group. This is working nicely. But I don’t understand why the value that is set to the group, is not displayed on the sitemap like with other (string) selections I have?
For instance: I set ‘TV-lights’ to 30%, and I can see in the log this is what the three lights above the TV are set to. But after setting the lights, the group will display just the drop down arrow, and when opening the drop-down, it wil show a bullet underneath all others, without text.

items

Group:Dimmer:AVG gVerlichting_TV "Verlichting TV" <light>
Dimmer TV_1     "TV 1" <light> (gVerlichting_TV) {channel="hue:0100:00178:14:brightness"}
Dimmer TV_2     "TV 2" <light> (gVerlichting_TV) {channel="hue:0100:0017:15:brightness"}
Dimmer TV_3     "TV 3" <light> (gVerlichting_TV) {channel="hue:0100:0017:16:brightness"}

sitemap:

Selection item=gVerlichting_TV mappings=[0="uit", 10="10%", 30="30%", 50="50%", 90="90%", 100="aan"]

How can I get the current setting on the drop down on the sitemap?

Try that:

Group:Dimmer:AVG gVerlichting_TV "Verlichting TV [%s]" <light>

Unfortunately, that doesn’t change anything. I came up with [%.0f]since the value in the log is with lots of decimals, but the mapping is without. But that doesn’t work either.
I always put the labels in the items files, but I also tried changing this on the sitemap this time, with no effect.

Bytheway, I had forgotten to upload my screenshot:

Hang on, I see errors about my former formatting rules pop up in the log file when I use the sitemap, although I already changed that. I have to go now, but will test further tomorrow and maybe clean the cache?