Login form loads infinitely if account use to login is a Admin

I found an issue with Membership 2 Login form. Login form URL: https://adieusymptomes.com/se-connecter-2/

I'm using this shortcode to generate a login form:
[ms-membership-login register="no" redirect_login="https://adieusymptomes.com/programme/programme-vie-sante"]

When you login as a regular member, the login functions as it should be. But when you login using an Admin account, the page loads infinitely.

We checked our server error logs and this is the issue we see related to the issue:

[Thu Jul 30 15:22:30.927204 2015] [:error] [pid 106034] [client 197.15.245.208:49917] PHP Fatal error: Maximum execution time of 600 seconds exceeded in /home/bonheurenv/domains/bonheurenvrac.com/public_html/wp-content/plugins/membership/lib/wpmu-lib/inc/class-thelib-array.php on line 176, referer: https://adieusymptomes.com/se-connecter-2/