Hi Tracy,
Thanks for the post.
Can you please go to the "Support" link from the top right corner icon and send us the snapshot of the page? Also, let us know if you have the option "Reset password after exclusive use" enabled in the Access Control configuration page. If this option is enabled, PMP will auto check-in the password after the time frame expires and reset the password in the target system. Also, let us know the browser version that you are using.
The above details should help us in simulating this issue here in our environment. And we should be able to get back to you with a proper solution.