When a virtual user is logged in, the time of response of the login page might be longer than expected. The issue might appear after completing 2-3 login procedures by different virtual users.
To resolve the issue, consider one of the following options:
- Upgrade Sitecore XP instance to Sitecore XP 9.2 or later.
- For Sitecore XP 9.1.1, download and install the corresponding cumulative hotfix available in KB1001330.
- For Sitecore XP 9.1.0, download and install the corresponding cumulative hotfix available in KB1001328.
- For Sitecore XP 9.0.2 and earlier, download and install the patch compatible with the affected product version found on this page: https://github.com/SitecoreSupport/Sitecore.Support.316302/releases