I solved this problem on S10e using [this guide][1].

1) [Root your S10][2]. This step is required.

2) Install [BuildProp Editor][3] (or equivalent) and run it, grant it root permission

[![enter image description here][4]][4]

3) Touch the pen icon at the top

4) Scroll to the very bottom of the text file, and add the following two lines:

    fw.max_users=3
    fw.show_multiuserui=1

[![enter image description here][5]][5]

5) Touch "Save and exit"

6) Check that the lines are correct. No extra spaces, all characters written exactly as below:

[![enter image description here][6]][6]

7) Reboot

8) In Settings, search for "Users". You can now add new users:

[![enter image description here][7]][7]


  [1]: https://beebom.com/how-enable-multiple-user-accounts-any-android/
  [2]: https://android.stackexchange.com/questions/212265/how-to-root-samsung-galaxy-s10-s10e-s10
  [3]: https://play.google.com/store/apps/details?id=com.jrummy.apps.build.prop.editor
  [4]: https://i.sstatic.net/hFqMA.jpg
  [5]: https://i.sstatic.net/lI8pe.jpg
  [6]: https://i.sstatic.net/SW5mT.jpg
  [7]: https://i.sstatic.net/7KgHG.jpg