Since I started my current role, since my hiring, my manager and I agreed on a set of extra, more senior tasks, for a bigger, "parallel" team. These tasks were done unofficially. I manifested my will to officially perform those seniors tasks for both teams. The manager of the bigger team was positive and wanted to create a new role for me to allow me to do so. I wrote my own role description and shared it with both managers. The role is exactly what I have been doing for the last year, there are no divergences in it, but it is more senior (as it incorporates officially those senior tasks!)
My line manager told me that now I can still perform those tasks, but I have to strictly do them from his team, and I have to go through a specific internal process for 1-2 years I want to be promoted to the role I wrote (which is what I do today, and what I would be doing in this setup). The manager of the bigger team wants to maintain a good relationship with my current manager, and she is not discussing the matter at all right now.
Question: Is it common in a corporation to perform unofficially in a senior role for 1-2 years to deserve to be recognised for work you have been doing for 1-2 years, or is this a red flag and I should leave?