I have a microtik R11e-4G_V005, and I have such a problem. I will use Quick Set and connect to the Internet without problems with LTE.
After some time, after an hour or after a few minutes, the Internet crashes and stops pinging on 8.8.8.8. Neither Mikrotik does not work, but routing and work on Ethernet and connection via Winbox is fine.
When I restart the lte interface or bridge or ether it will start again. He does it many times a day. Do you know what it could be.
Thank you for the advice.