I earned 1.35 million XP in one go

So when I was driving around I unlocked 51% of the map. "Cool I get some XP" I thought to myself. I then saw my XP bar and it stated that I earned 1.35 million XP. I thought it was a visual glitch so I observed how I was gaining XP but I simply gained level after level, resulting in me jumping from Level 37 to 43 in one go!

I was curious to see if this was repeatable so I drove about and unlocked the next % of road. Funnily enough the game stated that I discovered 85% of the map. So my theory is that the game was not counting the % correctly and when it synced with the server-side data, it corrected the XP gain. Has anybody else experienced this?