Sorry, my Finnish is still bad.
I also recently bought and Elli pro box with VW logo for the budget price.
The box works and has been installed to wall, but the automatic software update is failing, staying on the ancient v2.14.4.
After being online for 12-14 days, finally the VW app reported failed update. Before that, 29 attempts was displayed. Seems like around 3 attempts per day.
(Interestingly the Elli and Skoda app does not show the number of update attempts. Btw, the box can be easily paired to any of the app, after unpairing from the previous.)
I've been in contact with Elli support through phone and email and I was informed that update fails due to some certificate issues. I did not get the deeper technical details.
I was told that they are handling the case with high priority and I just need to have the box powered and connected to Internet. As far as I understood, the LTE must be disabled.
Similar issue has been discussed on a German forum:
Keine Verbindung zum Elli-Server - VW ID Forum
As far as I understood, Elli support needs to execute a manual interventions to sort out the certification issue, which might be due to extended time the box spent without Internet connection.
So I'm just waiting now.