It's strange that the Overview Button works sometimes and not others. I noticed the issue when I started messing with the setting in Chrome to "Merge tabs and apps" but either setting in there doesn't fix it any more.
No, I haven't tried a factory reset. Do you mind telling what that entails and what I'll loose and what I'll have to reload?
A factory reset will bring your device to factory settings like the day you got it. You can always back up our contacts, texts, pictures, videos & documents on Samsung Kies. Download Samsung Kies on your computer & then plug in your device into your system. Back it up & then do it. Restore everything afterwords.
You will just lose all the apps & you will have to redownload the apps. That is all.
I backed up my Alpha with Helium and got Rogers' 4.4.4 ROM installed and running. The multi/overview/recent apps button now works perfectly but downgrading has its other headaches. The Helium backup won't restore on 4.4.4 so I had to login to tons of accounts and install all my apps manually. I got most data back, but there are a couple games that I have redo 100 levels now.
The other major annoyance is that now there is an icon on the top bar asking for me to update to 5.0.2. It also has the update listed in the Notifications and says "Update postponed". The lock screen in Lollipop is much better than KitKat and I may need to install NiLS again.
I know the multi/overview/recent button is a common issue with the Alpha on Lollipop, but I'm tempted to upgrade again and see if it works. I can't find any definitive answer as to whether it's a known issue or ananomaly. I guess I should probably wait for 5.1.
I had lots of trouble finding info on this issue, so hopefully my experience will help someone else.