I have been fishing at Talador at phase-less area (the south island of the lake near the bounty quest Riverbeast).
I haven't use water walking and simply stand still.
Btw, after the bag i'm on 233 casts and no 2nd lunker 0_o".

If still wonder the bag still exists ::(
Fish today for Blackwater Lunker and got it.
I dunno what to do, keep farming or wait till it get fixed.