It seems to be not possible to unlink animation (power) for 2 or more lights (point lights) previously linked with Ctrl-L > Link Animation Data
Selecting the light and choosing Make Single User - Object Animation makes just nothing, when I try to move a handle in dope sheet, it affects all the lights.
I've tried it in 2.91 (official) and in the latest alpha 2.93
Is it a bug or am I doing something wrong?