All new members showing incorrect expire date

Hello Team.
We just set up a new install of the membership plugin with two levels (visitors and registered users) with a free subscription plan and set it so that all of the existing wp users who already had accounts because registered users. We set it the plan with an indefinite date, HOWEVER when we look at the membership list from All Members, the all show an expiration date of 20 days from the day we turned it on, or a new registered user would show a date, 20 days from the creation of their new account.
The way I understood it the indefinite setting means it never expires, so why is there an expiration date and how do we fix that or do we even need to?
Thanks so much, we would liek to get that resolved ASAP as we have over 11000 users who would be upset with us if they sudenly could not get their content.