Back in Alpha 20, I used to make elevated maze-like structures for zombies to path down. The idea behind them was that if I put down a loooooooong path with a whole bunch of turns, it would take the zombies a very long time to reach me. Meanwhile I would be at the end of the path with robotic turrets mowing the zombies down while they could never touch me. I'd even add a few cube blocks along the path that'd force the zombies to stop, jump up, then jump down.
The idea worked 100%, but I noticed back in A20 that zombies who haven't been damaged in a while will go into that 'rage mode' where they stop and attack nearby blocks. Shooting them with a single pistol round would solve the issue; they'd immediately start pathing towards me again, and if I had turrets down they'd do a good job of chewing up the zombies and interrupting the rage mode.
I assume that this behavior is in fact intended because I've seen streamers and video creators mention that zombies go into rage mode based on proximity. Cautious Pancake's 6000 foot maze mentions a 'magic 11 block radius' and it's visible in the video where when a zombie gets within 11 blocks of a player even if they haven't been damaged they can stop and go into rage mode.