I was running into this same issue, however I did not receive a crash or anything when I zoned or died. The bots would simply despawn and I would have to respawn them.
After some investigation, I was able to fix the zoning issue by commenting out the the Depop(); line in:
https://github.com/EQEmu/Server/blob.../bot.cpp#L6960
I was also able to prevent my bots from despawning when I die with a couple other changes. Now when I die, my bots do not despawn but instead my group gets disbanded and my bots zone to my bind spot with me.
What I would like to happen is that when I die my bots stay where they are and continue to fight until they die also or better yet win. That way when I die they could Rez me to where we they are (assuming they didn't die also) and I wouldn't have to run back. I'm not sure if this is possible since looking at the code it seems that anytime the client zones the bots zone along with them.