One of the factors perhaps influencing everyone's behavior is that Biden's staff would presumably like to be "in charge" or heavily involved in a Harris campaign, whereas donors etc. might be inclined to totally clean house.
The dynamic where, on the one hand, they're trying to prevent the ship from sinking, but on the other hand, they want to secure a position on the first-class liferaft off the boat, is one of the reasons the equilibrium is shifting quickly.