coc-flutter stopped working after changing Flutter version to 3.10.5

**Describe the bug**
I have two Flutter projects, both on version `2.10.5`. Now, I decided I have to bring them to the recent version `3.10.5`. After changing my Flutter version, fixing all dependencies to the latest versions and restarting Neovim, `coc-flutter` isn't working for several actions.

- doHover does not work
- jumpDefinition does not work
- No quickfix actions are available where they definitely should be available
- Rename provider isn't available for refactoring
- Warnings and errors from `coc-flutter` still show in Neovim
- The plugin is still loads and other hotkeys work
- I notice that I have to save so changes will be considered so that warnings and errors go away
- Tooltips are gone entirely
- The other project that is still on Flutter 2.10.5 still works with `coc-flutter`

**To Reproduce**
This is rather a cry for help. How could I please approach this issue? I'm pretty sure you cannot reproduce it, as it would mean that this plugin is not compatible with Flutter `3.10.5`

**Expected behavior**
The project is pretty much broke, because of null-safety problems and other issues such as API changes. However, I would still expect it to be able to jump to definitions or quickfix things that it clearly complains about, like the notice that string interpolation isn't allowed anymore. Also no tooltips work. This is a big pain for me, because I have to repair the project.

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Desktop (please complete the following information):**
- OS: MacOS 12.6 (21G115)
- Vim or Neovim: https://github.com/nvchad/nvchad/ and https://github.com/martin-braun/cocchad (Neovim)
- (Neo)vim version: v0.9.0

**Output channel:**

1. Set `"flutter.trace.server": "verbose"`
2. Restart coc using `:CocRestart`
3. Reproduce the issue
4. `:CocCommand workspace.showOutput` open output list and select `flutter`

There is no `flutter` available, so was I wrong in thinking that `coc-flutter` loads?

**Config**

https://github.com/martin-braun/CocChad/blob/v2.0/coc-settings.json

Could you please give me advice how to debug the problem?