I don't have an F310 or any dread, so can't be exact, but from spec. and owning a Yamaha APX which came with EXP26s, ex-factory at the F310's entry level price point I'd suspect Yamaha OEM. IDK if they are repackaged OEM D'Addario of any sort. Neither Yamaha Music's AU or USA website specify for the F310, so it's anyone's guess.

I use D'Addario EJ16s and they suit me, but I love Concert body bright and detest Dreadnought body boom. I also prefer the EJ16's price vs EXP26s, which facilitates more frequent replacement. Cheaper lesser quality strings and old strings will frequently be relatively boomy in the same gauge IME, so your ears may well just be accustomed to that.

As Ben said, new strings also require a bedding in period regardless of stretching when you fit them, during which they will go out of tune easily (flat).

Give them and your ears a week to adjust. If you still don't like them, experiment. Plenty of choice out there. Try EXP26s if you're prepared to pay for them. They are very nice to play, but to my ear as fitted to my Concert Cutaway, they too sound bright albeit with solid projection. I suspect they'll project a more prominent base tone on the Dread's full body.