Using a third party class in CI4

I want to use the influxdb-php class in CI4:
https://github.com/influxdata/influxdb-php
I tried calling the class from the controller using:

PHP Code:

use InfluxDB;
use InfluxDB\Client;
use \InfluxDB;
use \InfluxDB\Client; 


But no success. I installed it using composer:

Code:

composer require influxdb/influxdb-php

use InfluxDB\Client;

new Client(.....);

I'm still getting the following error:

Code:

Class "InfluxDB\Client" not found

When using:

PHP Code:

use InfluxDB\Client;
// and
new Client('localhost',8086); 


CI 4.2.0 installed via composer (updated to 4.2.1)
influxdb/influxdb-php - installed via composer.
Works.

Have you done any manipulations with the structure of the application?

None that I'm aware of. What should I look out for? Where can I look?

By default, the vendor directory (where the composer stores the autoloader and packages) is in the root directory.
If you have changed the directory structure, you must ensure that the COMPOSER_PATH constant (app/Config/Constants.php) points to the correct path for the composer autoloader.

It appears to be fine:
defined('COMPOSER_PATH') || define('COMPOSER_PATH', ROOTPATH . 'vendor/autoload.php');

I have myth-auth installed and operational as well through composer. So I don't understand why specifically the InfluxDB client won't load.

"Solved" is by re-creating a new CI4 install, installing the required packages using composer, and copying over the controllers, models, views etc. from the original install. It works now...