I am NOT an instructor, but I have been playing fairly well for 46 years.
I've found that the 2nd. ball break does not spread the balls as much as a well struck 'normal' break. My guess is that you may have mis-hit an early on break, saw the results, & are trying to hit the break harder, & maybe due to trying to over do it, are still mis-hitting. l would suggest that you start off when next breaking that you really focus on good tip to CB contact & soild CB to apex ball contact. Watch the CB after contact to tell you how you hit it. If you make solid contact & the balls still do not spread then it is either the 'rack' is bad as an earlier post suggested or the table is just that slow.
ALSO, was the apex ball the one(1) ball? Some opponents will use another ball because over much time & use the one(1) ball will wear down due to always being the ball struck on the break & will become a bit lighter which promotes a bigger spread. Using, say the six ball might inhibit the spread over the maybe lighter one (1) ball.
That's my nickel's worth.
Good Luck,
Rick