Read the statement by Michael Teeuw here.
UNSOLVED Pushbullet trouble
I’m using the Pushbullet module and all is well when I first start the MM2. However, after some time (usually days) messages to Pushbullet no longer display on the MM2. Those messages do appear on other devices connected to Pushbullet. I’ve thought it was because of a wifi drop, but I can remote into the Rpi using PuTTY while the Pushbullet messages don’t display so I don’t think it’s that. Can anyone suggest where else I should look to solve this problem??? Thanks!