I got this Question just this week.
So I am going to try my best to answer it.
Why are my crochet row ends uneven?
1. You added a stitch or two.
2. You left off a stitch or two.
3. You skipped a stitch.
4. You got off count.
That seems easy enough -- But, how did you do that?
See The Video on my Youtube Channel at this LINK
Check the crochet pattern you are working on.
Does it have a "Notes" section?
It should tell you if the ch or chs counts as a st.
If it does not count as a stitch you begin your next row in the 1st stitch,
But If it does count as a stitch you begin your next row in the 2nd stitch.
Also, Count your stitches to make sure you are keeping the right amount of stitches per row.