Who I have the same questioned this topic

Yesterday morning, it seems my Galaxy 8+ sent two text messages to one of my contacts on its own.  I did not send the texts and had the phone in my hand at the time.  I downloaded Airbnb app and was having a hard time logging in to the app.  The sent messages did not appear in the text conversation between my contact and me.  The Verizon text log suggests that my phone sent the two texts.  What might account for this?  a virus?  an app?  I don't recall downloading any apps over the weekend aside from the Airbnb app.  This has never happened before and it hasn't happened since.  It's concerning though because the content of the text messages (text only; no links or promotions or images) was realistic (e. g., one text talked about cherishing moments spent together).  Thoughts?  Suggestions for preventing this from happening again (change mobile number?  factory reset?  other?).  Thank you.