First: yes, placing it from linked container is correct. There are multiple reasons why it might fail - even tho I think that got fixed, in the past the linked container sometimes didn't work properly. Relogging and reset/relink the container could help.
Then make sure that your linked container is selected: you can see the "link icon" above your inventory next to the "box icon" - it should be selected and means that the linked container is your active container. You can switch the active container by clicking on these icons or pressing ctrl+i on your keyboard. It will give a message "switched active container to...".
Last thing that comes to mind is that there was/is an issue where you can't place claimed elements. Look at the symbol of the scanner - if there's a "person icon" on it, it's claimed and you should right click and "unclaim" the element before you try to place it again
Minus got a reaction from NQ-Naunet in territory scanner how to place?
Minus got a reaction from vertex in territory scanner how to place?
Minus reacted to vertex in territory scanner how to place?