AP firmware 3.9.4s004 build 5007 is the special firmware created to handle the 2.4GHz SSID data rate to using the minimum data rate settings when the channel conditions is in very congested conditions.
In the 3.9.5 GA firmware, the 3.9.4s004 working method is not directly integrated into the latest release while we have better improvement way to work on the data rate selection. As discussed with the Engineering team, we would suggest that you can use the 3.9.5 GA firmware and recheck the WFI 2.4Ghz client connection conditions. Feel free to create a ticket to support team to verify if you see any thing not working as expected
ok thanks. another question, if i use a special firmware and select special settings then switch to a GA release, do the special settings stay programmed even though the option may be removed from being visible or does it remove the special settings automatically when updating to GA?