@Whatamidoing-WMF sent me this quote on Friday:
Comment I tried it at the test Wiki. I was prompted for my choice when I attempted to edit. I picked the "always show me both tabs" choice. The page reloaded but I was only presented one tab, which is confusing. Upon my next edit, it did in fact start showing me both tabs. But have me choose "always show both tabs" and then sending me back to the edit window with only one tab makes a user wonder if it took effect or not. Jason Quinn (talk) 12:39, 1 April 2016 (UTC)
I reproduced the issue earlier.