We have not managed to replicate the problem you have with the cog and pin, but we are working on adding more extensive logging to the UI. It would be great to see your logs after we release that version, to try and see why you are having this problem.
The launcher only remembers pinned accounts.
Regarding the names of previously logged in users not being remembered: Login no longer auto-completes previously logged in accounts - #22 by CCP_Avalon
This rewrite of the launcher UI does not remember pinned accounts from previous versions, and it does not remember what profile you have selected for each of them. So you will have to login with all the accounts you use and if you are using other profiles than Default, then you have to change the profile manually for all of them. You will only need to do this once. Next time you login with an account you have logged in with before, it will remember what profile it should use.