Profile leak bug in Signal (app)?

Woke up this morning to a text from an acquaintance. When I hit "reply" I was startled to see the input field had my picture (which I've never put into Signal) and my name showed up as "A Guy". I happen to know that my ex-girlfriend used that picture and that name in her phone for me. We haven't spoken in months.

Obviously this is alarming. I keep "notes" as contact names for lots of people in my phone. e.g. "Jenny" might be "Jenny Nutcase" or the like. Are all my contacts somehow getting this info from my phone too? Yikes.

Can anyone confirm? (Android 9, Signal 4.53.7)

(Yes, I know this isn't the place to report bugs, but I thought this community would be interested.)