When selecting one or more entries from the Sales Quotes OWL, the action 'Set as Lost' is sometimes available, and sometimes not.
However, when opening the object you are able to perform the action from within the TI.
SAP Cloud for Customer
The action "Set as Lost" in Quote OWL is only enabled for quotes with progress "Pending".
If you select several quotes, it is basically the first selected quote in the list, that decides if the action "Set as Lost" is enabled or disabled.
This is expected system behaviour.
From the object TI, it will be possible to perform other actions.
Not all actions available in the TI are available from the OWL.
set as won , KBA , LOD-LE-CQP , Customer Quote Processing , How To