An alpha release got automatically installed

One of my websites just informed me that WordPress got updated. I expected it to say it was updated to 5.5.2 but instead it updated to 5.5.3-alpha-49449. I checked by logging into the site (not through the email just in case) and verified that it did update to an alpha build. I don’t know what would trigger this and I don’t remember setting anything or installing anything that would allow this. What could have caused this? My other sites successfully updated to 5.5.2 so I find it odd that this one would load an alpha and not the others. It does give me the option to re-install 5.5.2 so I should be okay. I just find this odd.