It's lollipop - After 2 hours of tech support with Verizon, and the Verizon Tech calling the Samsung Tech, I was told the stock Samsung Messenger App with Lollipop no longer had an alert for open SMS Messenger because "If it is open, it means you are looking at it." <eyeroll> I explained to them that I was waiting for someone the other day after texting them "I'm ready" then I proceeded to put my shoes on, they sat outside my house and texted me 10 times to let me know they were waiting... with no alert. The same issue with the stock Calendar, stock notifications don't work, however if you choose the dropdown choice "email" as the alert it works, but then you have to clear out your email because it is filled with emails of alert notifications.
After looking at the 3rd party choices (for hours) I installed both SMS KK and Calendar KK, I paid for the Prime version. I love them. I disabled the stock apps afterward. I have no idea what back processes these 2 stock apps were running but since I disabled them my phone's battery life has doubled and everything is running smoother/faster.
Finally, I am considering disabling the stock Galaxy S5 camera app because the Lollipop update has affected it as well. Autofocus is iffy, as soon as I open it the phone gets hot and the battery drains rapidly. I have 2 other Camera Apps on my phone already and neither of them have performance issues.
I hope this helps others, and thank you both for helping.
I'm just curious if both of your phones run the Lollipop OS (OS = operating system)? My phone is a Verizon Galaxy S5 and the issues only occured after Verizon forced me to update from KitKat to the new Lollipop OS. I declined the update because I was aware of the issues, until Verizon no longer allowed anyone to decline. It is my understanding that some carriers don't have Lollipop yet, but I would think that a phone as new as the GS6 edge would have Lollipop as the original install regardless of the carrier.