I have the same problem with miner dropouts and can pretty much confirm it is an internet issue, I live in a rural area with very poor and unreliable broadband, and the miner dropouts coincide with internet dropouts.
It is annoying and a hassle to restart the miner every time that happens, especially since  I obviously can't do it when I am not at home. An auto-restart feature when the hash rate drops would be incredibly helpful. I also mine Ethereum with HiveOS, and they have such a feature implemented. For people like me with poor internet it is a real helpful feature.

One question ...my node is synched. Now, if I download Bitcoin Core Wallet from the official repo and install it (of course point it to the correct directory), will it just read the status of the blockchain from there, or will it try to sync again...what I definitely don't want to happen ?!