I had the exact same problem. I changed my settings for lock screen options under settings from NONE to SWIPE. Fixed my problem completely. Hope this helps!
After the most recent Gear update, mine did the same. I went into Gear Manager settings and discovered that all notifications other than Gmail were now turned OFF for some reason. I turned them back on and all is again working.
I am a novice at this but a tweaker and keep playing with the phone until I figure something out. I'm sure there's a the work around by one of the experts is on this forum but this is what I have done to make it work:
1. in setting, select Add Account
2. Select the @Email link and put my gmail user name and password in there
3. In the Gear Manager / Notifications I disabled the Gmail link and enable @Email (Thats it)
Now I get all my Gmail on my Gear with a Subject and approx 40 lines of the message (enough to determine if I want to read the rest on my phone)
Now for those that mess with the setting and are not getting anything instantly I have spent relentless hours trying to figure this out. What I have found is that after setting up your watch and Gear Manager just let it sit for about 4 to 8 hours (Usually mush less then that) and it just starts working. I have not idea why it just does. I guess it just needs to simmer