As I approached the beached boat where you fight the flying drone, Keener stayed on the little stone rampart and was immune. He was there the entire fight, and after the fight. I later saw his shadow, but no echo appeared, causing me to pull the network cord and then restart the client. Luckily it continued where i was and the echo showed up. This hasn't happened on any of my subsequent playthroughs, but was never solo again.
https://t.co/J8Lip9b2No?amp=1