Dear community,
I am facing similar issues w drop down list where I am unable to choose the option from the drop down list using the Action "Set Drop down list in window". However, I could not find a workable solution online.
I am trying to select the option by the index. Even when I put an index of "1", it still says select list does not contain index 1 while in fact there is a few options in the list as shown below. I am hoping not to use "Send Hotkeys" and when I Desktop record, it does not track properly too. Any help on this? Thank you!

Below is the detail of the error:
Microsoft.Flow.RPA.Desktop.Robin.SDK.ActionException: Failed to perform the requested operation on the drop down list (error while accessing the drop down list) ---> System.Exception: Select list does not contain option index: 1.
at Microsoft.Flow.RPA.Desktop.UIAutomation.Plugin.UI.UIControlElements.UIComboBoxElement.Select(Int32 index)
at Microsoft.Flow.RPA.Desktop.Modules.UIAutomation.Actions.AutomationRuntimes.UIAutomationRuntimeBase.SetDropDownListValueInWindow(IntPtr windowHandle, String selector, WindowDropDownListOperationEnum operation, ListVariantBase optionsToSelect)
at Microsoft.Flow.RPA.Desktop.Modules.UIAutomation.Actions.UIAutomationActionsDispatcher.SetDropDownListValueInWindow(Variant windowSelector, Variant dropDownListSelector, Variant optionsNames, Variant optionsIndeces, Guid windowId, Int32 dropDownListOperation, Int32 automationImpl)
at Microsoft.Flow.RPA.Desktop.Modules.UIAutomation.Actions.SetDropDownListValueInWindow.Execute(ActionContext context)
--- End of inner exception stack trace ---
at Microsoft.Flow.RPA.Desktop.Modules.UIAutomation.Actions.SetDropDownListValueInWindow.Execute(ActionContext context)
at Microsoft.Flow.RPA.Desktop.Robin.Engine.ActionRunner.RunAction(String action, Dictionary`2 inputArguments, Dictionary`2 outputArguments, IActionStatement statement)