Is someone else scoring the goals instead? If you are winning games it shouldn't be a problem, I have found that the strikers in the 2-5-3 will score something silly like 5 in 3 games and then go 5 games without a goal and usually when they are not scoring it means someone else is getting the goals instead. I think how the match engine works is that it calculates what the result should be and then creates the highlights and depending on who is in form etc decides who is going to score the goals, so for example if the ME calculates that the result is 3-0 to your team and for example your opposition are weak at set pieces and you have a good set piece set up then the ME may decide that you are most likely going to score from a corner thus one goal is scored by your centre back, then the ME may decide that your centre midfielder is in crazy form and he is the next most likely scorer and thus the other 2 goals go to him, this leaves no goals for your strikers even though they have done nothing wrong and in the next match it is just as likely the game calculates that they are the most likely source of goals and they knock in 4! It's nothing wrong with your strikers, it's just the way the game works and I wouldn't worry about it unless you are not winning games. I am currently using the 2-5-3 and am winning most games around 4-0, some games all 3 strikers will get the goals but when they don't score I am still winning 4-0 but other players are scoring instead. If the match engine allowed goalscoring players to score every game then you could soon build a team that wins 10-0 every game. It's all about calculating the most likely source of a goal during a match depending on mostly opposition tactics, weaknesses etc. It makes much more sense and is no big deal if you think of the match as just a bunch of numbers and calculations and the players are just numbered variables thrown into the calculator to decide a likely outcome. Rock classic is a great example..... You win many games with big scores but usually you will find that you go on a run and your centre mids will score all the goals and your striker will not score any or your striker will score loads and your midfielders score none, very rarely will you see the midfielders scoring loads in the same game as the striker because this would unbalance the result and unbalance the game as a whole like in old FM games when you would see 14-0 scorelines every other week.
You prob didn't want to know all that, so basically they will score when someone else who is currently scoring drops off form and stops
