AIBU to ask why my shower stream narrows in the middle?

[Beingseenisneedy]

Please help, can't find this on Google.

My new shower flows down but then curves inward in the middle, then straight down again.
Basically, like it has a belt in the middle of the flow.

Tried a different shower head, which was OK, but not the style of the shower.

What could be causing this please?
Thanks.

Limescale?

There are different settings on shower head . Have you tried adjusting that . One of my settings is like you describe. One is wide sprinkles , stronger ones , like massage ,etc.

It's one of these @Nofeckingway , so no adjustment to do.

It's a new showerhead ,new bathroom.

Global warming.