The problem is with the version code (the number after the + symbol), not the version name (the numbers before it). In Flutter/Android, the version code has to be unique and higher than any previous version you've uploaded to the Play Console.
No matter if it’s a major, minor, or patch update, the build number (version code) always needs to increase. This is because the Play Console relies on it to track releases and make sure updates are installed in the right order.