Since this event chain was being looked at and partially fixed last patch, I'd like to shed some light into it more.
Event name: "Mount up and help Fenn wrangle the panicked marmoxes!" AND "Escort Fenn back to the village"
Not blocking any progress or anything..but the rewards act as if it's from a living story 3 map. Check the screenshot. https://imgur.com/a/Umzo7sT
Event name: "Mount up and help Fenn wrangle the panicked marmoxes!"
This is blocking progress. There are not enough marmoxes that spawn sometimes. I've also waited for 10 minutes and not 1 marmoxes has spawned. Thus, stalling the event from ever progressing. Check the screenshot. https://imgur.com/a/U6MoMtF