I just had this happen in a game, here's my write-up:
Match ID: 18452161
Location: Blue lane, Amber side, between Guardian and Walker
Timeline:
6:00 - three of the four Amber creeps get stuck
- the next three creep waves proceed normally
8:00 - another couple Amber creeps get stuck in the same spot
8:30 - another Amber creep wave gets stuck
- Amber creep waves stop spawning in this lane
13:25 - Sapphire team notices where the creeps are stuck and begin clearing them
13:43 - one of the stuck Amber medic creeps dies
14:00 - the next Amber creep wave spawns normally and gets stuck again
14:50 - Sapphire creep wave reaches the stuck Amber creeps and clears them
- creep spawning appears to return to normal
