Personal Hotspot and "other devices" that have used data

Hello,

iPhone 7, OS13.4.1

I have not used my Personal Hotspot since swapping to this phone. I have not turned it on. The data amount used was 0.0 for months, which was to be expected with it turned off. When I looked today it says 5.3GB has been used. When I go to Cellular>Personal Hotspot, the devices connected were "Other Devices". Please see the now sideways picture below.

The only new thing I've done lately was use my Sonos app to play music on my Play:1.

Does anyone know what might be happening here?

Kindly,

Jay