When rebuild, Discourse removes PostGreSQL 10 and reinstalls version 9.5

Support Self-hosting
6

Classic installation, on a Digital Océan droplet, using this method discourse/docs/INSTALL-cloud.md at main · discourse/discourse · GitHub

(At least 2 years ago but I made many updates, this instance is on 2.5.0b3 and I try to upgrade to beta 4)