Enabling Create Button on M2O interface allows creation of new items in singleton collection

[adanielyan]

Describe the Bug

I created a singleton collection and added a M2O relationship from another collection to it. I enabled both the Select and Create Buttons in the interface settings of that relationship field. When I try to select an existing singleton item I see a plank panel and cannot select anything, even though there is a singleton item created. When I click on Create button I am able to create a new item in the singleton collection. I can see that there is more than 1 item in singleton when querying the db directly.

To Reproduce

1. create a singleton collection
2. add a M2O relationship from another collection to it
3. enable both the Select and Create Buttons in the interface settings of that relationship field
4. create a singleton item
5. (optional) try to Select that singleton item from related collection
6. click on Create button and add a new item
7. query the singleton collection

Errors Shown

None

What version of Directus are you using?

9.22.1

What version of Node.js are you using?

18.12.1

What database are you using?

Postgres 14 on RDS

What browser are you using?

Edge

How are you deploying Directus?

on a Ubuntu server

[github-actions]

Linear: ENG-457

[rijkvanzanten]

ha good find