SAP Logon field entry history has a length limit. So, if the input field is 255 characters long, the input history for it will not be saved. By default, history is saved for fields that are 49 characters long. This can be fixed by setting or group policy:
Regedit:
Hive: HKEY_CURRENT_USER
KeyPath: Software\SAP\SAPGUI Front\SAP Frontend Server\LocalData\
Value Name: FieldLenHistoryOn
Value Type: REG_DWORD
Value Data: 000000FF (255)
Action: Replace
