All the sessions disappeared when the user gets logged in TPXA.
Someone changed the users from dynamic to static and did not give access to their respective profile in TPX.
Either change the users back to dynamic or add the profile to maintain list of profiles for each user.
To add the profile to a user in TPX go to the TPX User Maintenance Panel for the user.
Select Option 5 Maintain List of Profiles.
Add the profile for the TPX User Maintenance Detail Table.
TPX User Maintenance Detail Table
Panelid - TEN0159
Command ===> Userid - TPXADMIN
Termid - A01NAB01
Profiles added here take effect only if you set Date - 04/22/19
the "Static User" field on panel TEN0125 to Y for Time - 14:06:45
Profile name(s) from which the user is built:
To add a profile to the list, do the following:
1. Tab to an existing profile, or, if there are no profiles in the list,
"Profile name(s)..." heading.
2. Type I and press ENTER.
3. Type the profile name in the space in the list and press ENTER.