I am using version 1.9.7.
When I make an arena group with oqueue, I mark everyone with symbols before starting the match. This helps for seeing teammates' positions through boxes, pillars, etc. When we get into the arena prep room, the first person in is assigned leader, and can mark teammates with marker symbols. If that person is running oqueue, which is highly likely, symbols are removed at random from teammates' heads, which can cause positioning confusing when looking for those marker symbols to locate teammates. Disabling oqueue and clicking "go dark" work around this issue.