909 (I think) Sort tab order setting is not working properly

[etc.]

1. Open "Settings/Folder tabs" and change "Use for sorting" to "Drive and tab name" and click "OK".
2. RMB click on an active tab and select "Sort tabs in ascending order".
3. Open "Settings/Folder tabs" and change "Use for sorting" to "Tab name" and click "OK".
4. RMB click on an active tab and select "Sort tabs in ascending order".
5. Open "Settings/Folder tabs" and change "Use for sorting" to "Lock character, drive, tab name" and click "OK".
6. RMB click on an active tab and select "Sort tabs in ascending order".

Result:
- I could not find any difference between "Lock character, drive, tab name" and "Drive and tab name". Both of them ignore lock character.
- When I set to "Tab name" and sorted ascending order, lock tab is sorted to the top of list.

BTW, when I changed setting and clicked "OK", sometimes tab order changed unexpectedly and sometimes not changed. Is this an intended behavior? I only wanted to change setting, did not want to change tab order itself.