The wheelie and double arrows are actually showing that you’re getting discounted levelling, think that’s 20% less XP needed per level, that you get until level 98. The 2x XP multiplier would be applied if you had triple arrows showing.
I’m going to assume that you ran out of banked XP that you had accumulated while being parked at level 60 and that’s why you’re no longer getting the 2x on XP. I know that’s what happened to me. Would’ve been nice for Zwift to show us how much banked XP we had remaining.