gmail keeps locking out outlook access

Gmail uses port 995 and 465 for sending and receiving email from outlook. Due to a firewall config problem port 995 was blocked for several days. While it was blocked a number of new gmail accounts were setup but users could obviosuly not get out. When port 995 was enabled again the new gmail accounts could still not receive email and kept prompting for credentials. Gmail accounts that were setup some time ago worked fine.

When I login to one of the gmail accounts that is not working via the browser outlook then starts to work again. If I go to gmail and look at account activity I can see account disabled entries with location set as unknown. There seems to be something in gmail causing the accounts to not be accessible from outlook until you login through a browser. This keeps happening to these same accounts. Any ideas what this might be?