For what it's worth, we've found that 3 things made tethering rock-solid for us. Now we're Nikon (and Mac) based, but ideas the same:
1. Separate the tether action form the image processing. That to mean find a solid piece of 3rd party software that links to the camera and drops the image into a hot folder for LR or C1 to p/u. Added benefit of not needing to restart LR or C1 if connection dies, etc. We've always found LR sloooww and unreliable to tether into and C1 not much better. We use Sofortbild for Nikon. Dead nuts reliable and picks-up re-connect immediately if turn off or switch cameras. LR (what we use0 has no idea Sofortbild is there and never hiccups.
2. Don't have any TB, FW or USB drives plugged in while tethering. Backup during breaks.
3. Good cables and a USB booster. TetherTools works well for us.
Tethering shouldn't be an issue in 2017, but alas....