Message + app on Google Pixel 3, phone is a whole ONE day old, so all up to date, has decided to auto create groups of "me" and "contact" texted.  It has destroyed message history between me and several people by putting my responses in a "me + contact" versus just all texts under the contact name.  This is a real problem because I have texts that need to keep together.  I did all the supposed fixes - clear cache, reset, and restarts.