Lookup Fields not showing in Linked Records

[ouranos]

On table A, I've added a linked record field to table B.

On table A, I can add lookup fields from the linked record on table B.

But on table B, I cannot add lookup fields:
> No available sources to look up. Add a lookup source, then try to configure your lookup again.

I created a new linked record field with the same configuration on table A and the lookup works both way. Is there a way to fix my original field to work both way too?

[Databaser]

Can you share some screenshots please? 

[ouranos · Accepted solution]

Oh my bad, when taking screenshots for this I realised I had another table which was a copy of table B and table A was actually linked to this one and not B!