nvim freezes on xdebug connection, then `Error starting Vdebug: <class 'EOFError'>` in the statusline

[l00sed]

I'm an Xdebug n00b, so excuse me if this is something dumb and I just don't know what I'm doing.
I believe my configs are setup correctly. I'm using nvim, but have Local by Flywheel for setting up my development environment. I could only find one other person on the Internet who's doing the same thing:
https://webdevstudios.com/2019/04/16/debugging-wordpress-with-local-by-flywheel-neovim-and-xdebug/
But I believe their tutorial is outdated.

Basically, I mark a breakpoint, start Vdebug. Then:
/tmp/xdebug.log

Started
Listening on port 9000

...nothing happens, until I go to localhost:9000; then:

Found client
Finishing socket server
Got connection, starting
create session
keymapper: reload_keys
start session

At this point, nvim is locked up. I can't move the cursor up or down, can't run any vim commands.
localhost:9000 is still spinning at this point and hasn't loaded anything. When I stop the page, nvim frees up again.
However, it spits out Error starting Vdebug: <class 'EOFError'> in the statusline.
The Vdebug buffers have never opened at any point along the way.

~/.vimrc

" Vdebug
let g:vdebug_options = {
\   "port"                : "9000",
\   "server"              : "127.0.0.1",
\   "timeout"             : 20,
\   "on_close"            : "detach",
\   "break_on_open"       : 0,
\   "ide_key"             : "vdebug",
\   "debug_window_level"  : 0,
\   "debug_file_level"    : 2,
\   "path_maps"           : { "/app/public/": "/home/dan/Local Sites/surgicorps/app/public/" },
\   "debug_file"          : "/tmp/xdebug.log",
\   "watch_window_style"  : "compact",
\   "layout"              : "horizontal",
\   "marker_default"      : "⬦",
\   "marker_closed_tree"  : "▸",
\   "marker_open_tree"    : "▾"
\}

php.ini

[xdebug]
{{#if os.windows}}
zend_extension = php_xdebug.dll
{{else}}
zend_extension = {{extensionsDir}}/xdebug.so
{{/if}}

xdebug.remote_enable=1
xdebug.remote_connect_back=On
xdebug.remote_handler=dbgp
xdebug.remote_port="9000"
xdebug.remote_host="127.0.0.1"
xdebug.idekey="vdebug"
xdebug.profiler_enable=1
xdebug.remote_autostart=1
xdebug.show_error_trace=On

nvim

NVIM v0.4.4
Build type: Release
LuaJIT 2.1.0-beta3
Compilation: /usr/bin/cc -g -O2 -fdebug-prefix-map=/build/neovim-aKIhK1/neovim-0.4.4=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=1 -DDISABLE_LOG -Wdate-time -D_FORTIFY_SOURCE=1 -O2 -DNDEBUG -DMIN_LOG_LEVEL=3 -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fno-common -fdiagnostics-color=always -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -I/build/neovim-aKIhK1/neovim-0.4.4/build/config -I/build/neovim-aKIhK1/neovim-0.4.4/src -I/usr/include -I/usr/include/lua5.1 -I/build/neovim-aKIhK1/neovim-0.4.4/build/src/nvim/auto -I/build/neovim-aKIhK1/neovim-0.4.4/build/include
Compiled by team+vim@tracker.debian.org

Features: +acl +iconv +tui
See ":help feature-compile"

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/usr/share/nvim"

nvim :checkhealth

health#nvim#check
========================================================================
## Configuration
  - OK: no issues found

## Performance
  - OK: Build type: Release

## Remote Plugins
  - OK: Up to date

## terminal
  - INFO: key_backspace (kbs) terminfo entry: key_backspace=\177
  - INFO: key_dc (kdch1) terminfo entry: key_dc=\E[3~
  - INFO: $COLORTERM='truecolor'

## tmux
  - OK: escape-time: 0ms
  - INFO: $TERM: tmux-256color

health#provider#check
========================================================================
## Clipboard (optional)
  - OK: Clipboard tool found: xclip

## Python 2 provider (optional)
  - INFO: `g:python_host_prog` is not set.  Searching for python2 in the environment.
  - INFO: Multiple python2 executables found.  Set `g:python_host_prog` to avoid surprises.
  - INFO: Executable: /usr/bin/python2
  - INFO: Other python executable: /bin/python2
  - INFO: Python version: 2.7.18
  - INFO: pynvim version: 0.4.2
  - OK: Latest pynvim is installed.

## Python 3 provider (optional)
  - INFO: `g:python3_host_prog` is not set.  Searching for python3 in the environment.
  - INFO: Multiple python3 executables found.  Set `g:python3_host_prog` to avoid surprises.
  - INFO: Executable: /usr/bin/python3
  - INFO: Other python executable: /bin/python3
  - INFO: Python version: 3.8.5
  - INFO: pynvim version: 0.4.2
  - OK: Latest pynvim is installed.

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