Kobalt electric mower not picking up all the clippings, suggestions?

I have a hand me down kobalt mower that’s about 4 years old. I’ve noticed it’s starting to drop more and more of the clippings each time I mow the grass (zoysia and st. Augustine.)
Ive never sharpened/replaced the blade on it and am wondering if this is the first step I should take to remedy the situation. Any suggestions are welcome.

Also, I try not to mow when the grass is wet because I know that makes it more difficult to get all the clippings but it’s still dropping a lot.