In some cases, a remote client connecting to a 4D Server may have checked off "Remember password" button during their last login to allow for the server to auto log them in the next time they try to connect, rather than re-enter their password everytime. However, this poses an issue when the remote client would want to log in using a different user credentials, but find themselves unable to.
In order to have these preferences forgotten, navigate to the database selection screen on the client machine, under the Recent tab, and delete that instance of connecting to the server. Afterwards, connect back to the server using the Custom tab, and the remote client will be prompted to log in as a different user.
Another way this could be done is deleting the 4DLink file from the client machine. The 4DLink file is what 4D uses to populate the "Recent Databases" menu, and is automatically generated when a local database is opened for the first time or when it is connecting to the server for the first time. Two folders are created in the local preferences folderws of the user: Local and Remote. The 4DLink files in these folders correspond to whether they are used to connect to local or remote databases.
The folders are found in the following location
Windows: C:\Users\UserName\AppData\Roaming\4D\Favorites vXX\
MacOS: Users/UserName/Library/Application Support/4D/Favorites vXX/
XX corresponds to the version number of 4D.