What is meant by the No Choice Rate? Am I losing that percentage of users?

Didomi does not measure traffic in the way that an analytics tool would but instead counts the displays of a consent banner. For instance, a single user who:

• Visits the site but does not make a choice,
• Leaves,
• Then returns and makes a choice, will be logged as two separate events: one for no choice and another for making a choice, despite being the same user. Thus, Didomi's Dashboards will record two events for this one user.

The "No Choice Rate" indicates the frequency at which a consent notice is shown but no action is taken by the user—neither accepting nor rejecting the consent. This does not necessarily imply a loss of users, but rather that those users have not yet made a clear decision about consent at that time.

To summarize: A "No Choice" event is recorded every time consent is sought but the banner receives no interaction from the user, meaning they neither accept nor reject the request. It is calculated by subtracting the total number of choices made from the total number of notices shown: No-choices = total notices - total choices.

You can learn more here