Magento update from 2.3.0 to 2.3.1 problem

Those instructions are to get from 2.2 to 2.3, which is a big upgrade requiring a lot of instructions.

The small ones are far simpler to do (e.g. 2.3.0 to 2.3.2). Just follow the steps listed in the Official Magento Documentation. It shouldn’t take much longer than 5 minutes because there aren’t many steps.

In fact I just wrote a set of simplified instructions based off the Magento Documenation I just referred to if it helps: Updating Magento 2.3.x to 2.3.x (via the CLI/Composer)