I know how you feel. After faction changing, I decided to do some touching up… replacing buildings with more useful ones, rearranging some plots; all costing me gold and garrison resources, of course. After I finished this, my last task was to setup the monuments. It was such a delightful experience. Thank you, Blizzard!
Just updating this thread to say a whopping 7 months later this issue is still a thing lol. Bug fixes on old content… they truly are on the absolute backburner
Just got my Master Draenor Crafter and thought I could finally put up my third monument…but nope! Disabled all addons to try as well, just in case, but still just says “Empty” as you scroll through the “selections.”
I might be doing something wrong? Still not working for me. 
FYI the Alliance Inn recruiter works
thats just mean
Bump - still bugged.
Just adding another voice; still nonfunctional as of 05/30/2023.
Same here .Hope it gets fixed
i mean its the closest we have to housing, be nice if it worked right.
Really would love it if this function was fixed! Putting another voice in, in the hopes this thread gets noticed!
6/17/23
Still not working…I just want to add a statue to my castle cries
I just discovered this. It is indeed broken. 
Many threads reiterate this.
6/22/2023 Still, yet another forgotten bug for a waste land of content abandoned. Sad, I really enjoy my garrison. I have just about everything I need here outside of the new crafting systems.
Chiming in. Was really looking forward to dressing up my Garrison, as I spend almost all my sleeping hours here XD
6-25-23……Still bugged.
Does anyone know how or if it is possible to change these monuments from the actual game file locations?
Update!! As of the new patch 10.1.5! Nothing!! Absolutely nothing!! 
Oh, there’s something in 10.1.5; now the Garrison Hearthstone toy doesn’t work either.
https://us.forums.blizzard.com/en/wow/t/garrison-hearthstone-v1015-toy-does-not-work/1629548
