If you're still having issues with mlm upper level,
Using your bot to 99 mining I would say that about 6-8months ago an update to your bot made mining upper lvl no longer efficient. Reason being, when the bot would mine in this one particular location (to the northernmost edge) the bot would continue to crash and not restart. Consider changing the bot path up top perhaps? Find a new one that works? At the end of the day, if you're sacrificing a little exp an hour to be able to bot flawlessly, and a new path would look more like a human anyways, it'll be worth it.
Peace man, goodluck!