Formatting a block of code erases it

[benwaffle]

Describe the bug
When I select a section of code and format it, it disappears.

Software
OS and version (e.g. Ubuntu 20.04): MacOS
Code editor (e.g. VSCode): VSCodium
Vala Language Server (e.g. git commit, or PPA/AUR version): 0.48.5
Vala version (valac --version): 0.56.1

To Reproduce
Source code repo: https://github.com/benwaffle/vala-gen-json

Steps to reproduce the behavior:

1. Clone the repo above
2. Check out commit 1af5858352bb3bd9e971c04c79a635fb2ba0341b
3. Open main.vala
4. Select lines 202 - 206
5. Format selection
6. bye