Hi @AlineAve,
Thank you for your question and welcome to the Bunnings Workshop community, it is great to have you with us.
I would start by ruling out that the door itself is out of plumb by placing a spirit level on the face of the door. If it is out of level, there may be an adjustment nut on the door rollers that can be adjusted with a spanner that is often provided by the door manufacturer. If not, the fix may be slightly more in depth.
If the door itself is not out of plumb, I would assume that the track has either been bent or knocked out of level in some way. If you put your hand up into the cavity, can you feel if the door track is loose?
If this is the case, you would need to gain access to the attachment screws for the top track. With all of the cavity doors I have installed, the screws have been inaccessible for adjustment once the architraves are installed.
You could use a Deta Powerful Magnet to try and locate screws in the architraves, but I'm not sure how lucky you will be. In my experience these architraves are generally installed with brad nails, which are much less simple to remove. It's definitely worth checking before taking any action though as if you can locate screws, it will be far easier to reuse the architrave.
To gain access to the frame to adjust, it is likely that you'll have to remove the architraves using a pry bar. If you are extremely careful, you may be able to reuse the architraves but there is a good chance you will need to replace the architraves. Once you have pried the architraves off, you may need to remove a section of plasterboard to get access to the screws.
Now you have access to the screws, you would need to relevel/bend the track depending on the cause of the issue.
Once the issue is fixed, you can then reattach whatever you removed to gain access to refinish the door opening.
This can be quite an in-depth fix for the beginner D.I.Yer, so if you're not confident in your abilities, I would suggest enlisting the services of a local carpenter or handyman for assistance.
Let me know how you go, happy to offer more assistance where required.
Jacob
