Can't detach flex-o-tubes

[expenses]

Hi, sorry if this is the wrong place to ask, but I'm having an issue where I can't flex-o-tubes from objects. I press 'x' and click on it, but nothing happens. When I've detached other objects they've gone a blue colour but it's green here. What am I doing wrong?

This makes the deployment notes for the Duna-Class Dropship impossible to use without moving the flex-o-tube into an inventory.

[TDplai]

Hold 'G', then drag it to Val's inventory. Also, aren't you meant to use an engineer? Consult the KIS book for more info.