For three weeks running now, my five person group have had problems being able to see and hear each other at the start of the game. We found last week that everyone swapping from Chrome to Firefox helped but this week we still had one player who we couldn't all see, no matter how many times we refreshed. We've been using Roll20 steadily for two years with only minor hiccups but have had to resort to FB video call to be able to see and hear each other.