Should I be worried? Seam in ceiling drywall feels soft
I noticed that this seam in my kitchen ceiling drywall was looking more pronounced, and when I prodded it, it feel soft (you can see where my finger made an indentation). I pressed down with my fingers along the seam on either side and felt some slight "give" but nothing that actual broke the surface.
I'm slightly paranoid because the affected area is directly under an upstairs shower. Other than this seam, however, I don't have any reason to suspect the shower is leaking, or has any issues beyond the occasional wet bathmat.
For context: this is a townhouse (built in the mid-1970s) in southern California (mild/mediterranean climate).
On a scale from "It's fine" to "Call a contractor yesterday", how concerned should I be? Happy to give any additional details that might help.