Live Co-op vs AI bots' AI seriously bugging, typically freezing

Bot has been freezing sometimes(1%~2%) since the AI update, but recently they have been freezing crazily. 100% happens every bot game, and 20 to 30% whenever you encounter them. (The percentage following are just my feelings, they are the chance of meeting the situation in ONE game).

According to my 2000+ bot game experience, the freezing behaviors can categorized into two different types:

1. fail to perform auto attacks. The bots engaged with a player then failed to auto attack. They can cast spells but just won't auto. Typically happens on melee champions with more than 40% chance, though ranged champions happens 10~20%. Notice that they auto attack normally to farm. It happens only when trying to attack players.
2. Stucking in minions and failed to make a decision. The has be happening on karthus bot for a while,but not it's spreading to many other bots two.

Well, by the way I started a game on pbe with only bots and watch them playing, intermediate bots took 30 minutes to win over beginner bots. The bots freezes less than live, but still happens. I find something that can be improved for some bots' AI.

I notice that Irelia bot has never use her ult aggressively(even in a 1v1 all in or teamfight), and miss a kill 4 times because of that. I think allowing irelia bot to use her ult more often would be good(afterall it's a low cooldown ability). Xin Zhao won't activate all his 3 abilities when trying to attack. Maybe because he use his w frequently for farming. Adding a check if all of his abilities are off cool down and activate them at a time when using E will make Xin Zhao bot's attack much better. Cassiopea is impressive, not only at spamming her spells, but also kiting the enemy back with damage even when she's low and keeping herself safe at the same time.

I will test more bots if I have time in the future to find more possibilities to improve them :D.