Reseat Interior Central Air Vent Trim

Hi all,

Earlier today I removed the central and blanking trims around the AC control knobs for cleaning and managed to unseat the trim above surrounding the air vents. I've managed to reassemble the lower trim however the vent trim will not resit or click back into place even though it appears that all the tabs are correctly aligned! I'm also unable to completely detach it from the top.

Does anyone know/have any experience getting this to click back and sit flush?

Thanks.