npm removes installed Coffeescript after running any npm install

What's going wrong?

npm removes installed coffeescript
after installing > pm2 install coffeescript
running coffeescript files works fine
but
after running for example > npm i dot
(actually it was already installed, so just "empty" run of npm)
npm removes installed coffeescript (maybe because it was installed in main folder by > npm i coffeescript)
now running coffeescript gives error that no coffeescript installed

node version v16.13.2, npm version 8.1.2, Ubuntu 20.04

my solution

instead of > pm2 install coffeescript
do
ln -s ~/node_modules/.bin/coffee ~/node_modules/pm2/node_modules/.bin/coffee

How could we reproduce this issue?

pm2 install coffeescript
ls ~/node_modules/pm2/node_modules/
-- shows installed coffeescript libraries
running npm start test.coffee - ok
npm delete test
npm i dot
ls ~/node_modules/pm2/node_modules/
-- no coffeescript modules
running npm start test.coffee gives error:
[PM2][ERROR] Interpreter /home/jj/node_modules/pm2/node_modules/.bin/coffee is NOT AVAILABLE in PATH. (type 'which /home/jj/node_modules/pm2/node_modules/.bin/coffee' to double check.)

Supporting information

$ pm2 report

--- PM2 report ----------------------------------------------------------------
Date                 : Tue Feb 08 2022 08:07:02 GMT+0000 (Coordinated Universal Time)
===============================================================================
--- Daemon -------------------------------------------------
pm2d version         : 5.1.2
node version         : 16.13.2
node path            : /home/jj/node_modules/.bin/pm2
argv                 : /home/jj/.nvm/versions/node/v16.13.2/bin/node,/home/jj/node_modules/pm2/lib/Daemon.js
argv0                : node
user                 : jj
uid                  : 1000
gid                  : 1000
uptime               : 884min
===============================================================================
--- CLI ----------------------------------------------------
local pm2            : 5.1.2
node version         : 16.13.2
node path            : /home/jj/node_modules/.bin/pm2
argv                 : /home/jj/.nvm/versions/node/v16.13.2/bin/node,/home/jj/node_modules/.bin/pm2,report
argv0                : node
user                 : jj
uid                  : 1000
gid                  : 1000
===============================================================================
--- System info --------------------------------------------
arch                 : x64
platform             : linux
type                 : Linux
cpus                 : Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz
cpus nb              : 4
freemem              : 618680320
totalmem             : 2147483648
home                 : /home/jj
===============================================================================
--- PM2 list -----------------------------------------------
┌─────┬───────────────────┬─────────────┬─────────┬─────────┬──────────┬────────┬──────┬───────────┬──────────┬──────────┬──────────┬──────────┐
│ id  │ name              │ namespace   │ version │ mode    │ pid      │ uptime │ ↺    │ status    │ cpu      │ mem      │ user     │ watching │
├─────┼───────────────────┼─────────────┼─────────┼─────────┼──────────┼────────┼──────┼───────────┼──────────┼──────────┼──────────┼──────────┤
│ 0   │ jj_app_cluster    │ default     │ N/A     │ fork    │ 30487    │ 2m     │ 1    │ online    │ 0%       │ 142.2mb  │ jj       │ enabled  │
└─────┴───────────────────┴─────────────┴─────────┴─────────┴──────────┴────────┴──────┴───────────┴──────────┴──────────┴──────────┴──────────┘
===============================================================================
--- Daemon logs --------------------------------------------
/home/jj/.pm2/pm2.log last 20 lines:
PM2        |     at Process.ChildProcess._handle.onexit (node:internal/child_process:282:19)
PM2        |     at onErrorNT (node:internal/child_process:477:16)
PM2        |     at processTicksAndRejections (node:internal/process/task_queues:83:21)
PM2        | 2022-02-08T07:51:09: PM2 log: App [jj_app_cluster:0] starting in -fork mode-
PM2        | 2022-02-08T07:51:09: PM2 log: App [jj_app_cluster:0] online
PM2        | 2022-02-08T07:51:09: PM2 error: Error: spawn /home/jj/node_modules/pm2/node_modules/.bin/coffee ENOENT
PM2        |     at Process.ChildProcess._handle.onexit (node:internal/child_process:282:19)
PM2        |     at onErrorNT (node:internal/child_process:477:16)
PM2        |     at processTicksAndRejections (node:internal/process/task_queues:83:21)
PM2        | 2022-02-08T07:54:59: PM2 log: [Watch] Stop watching jj_app_cluster
PM2        | 2022-02-08T07:54:59: PM2 log: Stopping app:jj_app_cluster id:0
PM2        | 2022-02-08T07:54:59: PM2 error: app=jj_app_cluster id=0 does not have a pid
PM2        | 2022-02-08T08:01:37: PM2 log: [Watch] Start watching jj_app_cluster
PM2        | 2022-02-08T08:01:37: PM2 log: App [jj_app_cluster:0] starting in -fork mode-
PM2        | 2022-02-08T08:01:37: PM2 log: App [jj_app_cluster:0] online
PM2        | 2022-02-08T08:04:12: PM2 log: Stopping app:jj_app_cluster id:0
PM2        | 2022-02-08T08:04:13: PM2 log: App [jj_app_cluster:0] exited with code [0] via signal [SIGINT]
PM2        | 2022-02-08T08:04:13: PM2 log: pid=30462 msg=process killed
PM2        | 2022-02-08T08:04:13: PM2 log: App [jj_app_cluster:0] starting in -fork mode-
PM2        | 2022-02-08T08:04:13: PM2 log: App [jj_app_cluster:0] online

Start by running the reported reproduction: pm2 install coffeescript, then npm i dot, and verify the PM2 module and .bin/coffee paths. Trace the PM2 install and interpreter-resolution entry points involved in those commands. Done means a CoffeeScript interpreter installed through PM2 remains available after a subsequent npm install, with the provided reproduction no longer producing ENOENT.