Can't click on dropdown button selenium Python

I would like to click on the element "Project" to display the dropdown list (see image below) Using the selenium library in python elsewhere i get the error :

could not be scrolled into view

which is obtained, for instance, using this code:

driver = webdriver.Firefox()
driver.get(url)
driver.find_element_by_xpath('//div[@class="multiselect-container"]').click()

or using some code where I wait the element to be displayed, for instance like described here: Message: Element <option> could not be scrolled into view while trying to click on an option within a dropdown menu through Selenium

mySelectElement = WebDriverWait(driver, 10).until(EC.element_to_be_clickable((By.ID, "edit-projects")))
mySelectElement.click()

But I can't get it working.

Any would be appreciated.

The html source code may be found here:

https://rpidejr.hopto.org/f/8a909b51dcc34d09a00a/