Why is there sometimes a rescue pod icon in the HUD?

I noticed that sometimes a small rescue pod icon is displayed in the HUD. It does not show the position of the pod, it stays always in the same position:

_{(red circle by me for highlighting, not actually there in game)}

It doesn't matter if I'm in a vehicle, in a base, or just swimming around. I have the beacon of the pod disabled in my PDA. When I open the PDA and enable the beacon for my own pod the icon vanishes, but reappears after some time.

I first thought it is a hint to go to the pod for some reason, but I went there and couldn't see anything that required interaction.