Funny you should mention this, because I encountered exactly the same convoy behaviour on my last career patrol.
It was in June 1942, and I attacked a large convoy in one of the AL grids.
It was in broad daylight, late in the afternoon, and having got in very close (between the outer escort and the main body), I let fly with 4 eels, hitting a C2 cargo and a T3 tanker, both of which stopped dead in the water. Immediately, the whole convoy seems to go into panic, tankers and cargoes zig-zagging, stopping and swerving to avoid eachother. To add to the general confusion, the escorts come steaming in amongst their charges to start pinging and depth-charging me. As if that wasn't enough, I also had to endure a pasting from some low-flying catalinas and Liberators which also appeared!!
It was touch-and go, and I took some damage, which forunately my crew were able to control, and after a couple of hours or so, I managed to sneak out of there and the convoy and escorts gradually re-grouped and went on their way. I can only say that their erratic behaviour actually helped me to escape (being a daylight attack as well).
I should add that I'm not using any convoy mods in the game.
Hawkers
Captain, U46 (25 patrols and still going strong!!)
