I ran into the same issue. For me, it was due to installing bundler as a gem, which was generating gem scripts with the wrong gem version.

The answer @maximillian-laumeister posted also works, but if you don't want to modify generated files, you can install bundler via apt, which should take precedence over the gem-installed version:

sudo apt install ruby-bundler

The apt version of bundler should generate the correct gem scripts and match the system ruby version.