Had a similar issue with the box appearing in 2 bedrooms, back to back.
In bedroom one, a wardrobe with sliding doors, floor to ceiling, was made enclosing the box. The box can only be seen when a door is opened.
In bedroom two, I opened the box, and realised that it could be made smaller and reshaped, helping the aesthetics. The vanity units were installed, the left hand unit, lower door, covers most of the box, and the adjacent taller door covers the remainder, the plinth also helps to hide the box. It took a bit of planning, and again it's only visible when the doors are opened.
The box has now 'disappeared'. Might be some food for thought.
All the best, Tricky Dicky.