possible to vote twice despite vote based on invitation , and password not requested on smartphone

I created a test pollunit before our board (visio) next week to verify the number of presence.
I wanted to secure the vote with password and make sure that people can vote only once. So I set a password + "invitation requested".
In fact I was capable to vote twice based on the same email: once on my laptop (password was requested) and once on my smartphone (no password requested)
FYI, on my smartphone, I entered another name, so I can see the 2 votes

Hi Thierry,
can you send the link to your PollUnit to philipp@pollunit.com?
Then we can have a look. Please also provide us the password.
Kind regards
Philipp