Where is this? On your panel? If yes, may I know what is the height size of your panel? If 48px and below, for the sake of experiment. Could you temporarily try to increase the panel size to 64px?
Try to increase the panel size to 64px. I think this might be the case of chicken and egg situation.
Thanks for the help. Ya this is definitely due to my fix on index.theme to resolve issue on systray. Chicken and egg situation. If I reverted back index.theme changes that will cause odd size in systray.
For the time being, as a workaround if you want to use the smaller size panel and maintain the system settings icon to be the same as others, you need to manually map it to the system settings from scalable folder.
Symlinking the systemsettings from scalable folder worked perfectly. Thanks. As it is a change in the icons folder it will overwrite in the next update, right?
Edit: also works with the System Monitor one.
Yeah, can use this workaround
I see what I can do over the weekend. But please don’t give any high hopes
Don’t worry dirn, take it slow.
No need to hurry, I’ll be gone for 2 weeks starting this weekend. No updates for me anyway 
I didn’t get a chance to work on the new icons yet, but I did spend some time tweaking the index.theme file.
Based on my testing, the minimum panel height for the icon theme to use the scalable icons is 40px. Below that, certain apps (those with 40px icons, such as System Settings, System Monitor, Preferences, etc.) will fall back to the 16px icon set.
Feel free to give it a try on your end if you’re interested. Just remember to back up your existing index.theme file first.
YAMIS index.theme
[Icon Theme]
Name=yet-another-monochrome-icon-set
Inherits=Papirus-Dark,breeze-dark,Cosmic,Adwaita,hicolor
Comment=YAMIS by dirn
DisplayDepth=32
FollowsColorScheme=true
Example=x-directory-normal
KDE-Extensions=.svg
Directories=actions/16,actions/scalable,apps/16,apps/scalable,categories/scalable,devices/scalable,emblems/scalable,places/16,places/scalable,mimetypes/scalable,status/scalable,preferences/scalable
[actions/16]
Context=Actions
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[actions/scalable]
Context=Actions
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[apps/16]
Context=Applications
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[apps/scalable]
Context=Applications
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[categories/scalable]
Context=Categories
Size=64
MinSize=8
MaxSize=512
Type=Scalable
[devices/scalable]
Context=Devices
Size=64
MinSize=8
MaxSize=512
Type=Scalable
[emblems/scalable]
Context=Actions
Size=64
MinSize=8
MaxSize=512
Type=Scalable
[places/16]
Context=Places
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[places/scalable]
Context=Places
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[mimetypes/scalable]
Context=MimeTypes
Size=64
MinSize=8
MaxSize=512
Type=Scalable
[status/scalable]
Context=Status
Size=64
MinSize=8
MaxSize=512
Type=Scalable
[preferences/scalable]
Context=Applications
Size=64
MinSize=8
MaxSize=512
Type=Scalable
Plasma Monochrome Icons index.theme
[Icon Theme]
Name=plasma-monochrome-icons
Inherits=Papirus-Dark,breeze-dark,Cosmic,Adwaita,hicolor
Comment=plasma-monochrome-icons by dirn
DisplayDepth=32
FollowsColorScheme=true
Example=x-directory-normal
KDE-Extensions=.svg
Directories=actions/16,actions/scalable,apps/16,apps/scalable,categories/16,categories/scalable,devices/16,devices/scalable,emblems/scalable,places/16,places/scalable,places/symbolic,mimetypes/scalable,status/16,status/scalable,preferences/16,preferences/scalable
[actions/16]
Context=Actions
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[actions/scalable]
Context=Actions
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[apps/16]
Context=Applications
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[apps/scalable]
Context=Applications
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[categories/16]
Context=Categories
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[categories/scalable]
Context=Categories
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[devices/16]
Context=Devices
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[devices/scalable]
Context=Devices
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[emblems/scalable]
Context=Actions
Size=64
MinSize=8
MaxSize=512
Type=Scalable
[places/16]
Context=Places
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[places/scalable]
Context=Places
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[mimetypes/scalable]
Context=MimeTypes
Size=64
MinSize=8
MaxSize=512
Type=Scalable
[status/16]
Context=Status
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[status/scalable]
Context=Status
Size=64
MinSize=29
MaxSize=512
Type=Scalable
[preferences/16]
Context=Applications
Size=24
MinSize=8
MaxSize=28
Type=Scalable
[preferences/scalable]
Context=Applications
Size=64
MinSize=29
MaxSize=512
Type=Scalable
@dirn I have reverted the workaround to try this index.theme and it works very well.
Latest update is out!
Includes tweaks to index.theme.
- added
- apps/Beeper
- apps/krdc
- apps/latte-dock
- apps/re.sonny.Junction
- apps/trackma
- actions/document-scan
- actions/document-scan-symbolic
- places/folder-development
thanks, its in good shape again 
last update before vacation from updates btw, you made it in time 
I thought you’d already left for your vacation.
in less than 24 hours i will 
Do I still have to test the theme file? Or is it part of the new update already?
Mine is 72px. 
No need to test. It’s part of the new update already 
Cool! 
Great! As always, thanks a lot! 
You’re welcome 