I recommend fishing at 1 point for a couple of days in a row, you will get a continuation after 2-3 days, if you have already finished the mission with Kitty, then this is probably a bug in the game.
Maybe it's completely random, but I received many times combination 1+ 3- 1+ buy a fishing rod once, but then it was random. I want add function buy a shovel (and have random worms) or buy worms in future.
A little more and you can do it as dls (you can not play most dls for games, but this is a little secret)
Update: I fixed my mistakes so ignore the "edited"