You are not the first person to visit this forum with this situation. Notice, I did not say problem because you, personally, do not have a problem.
First, most of Chopin's students were female aristocracy, and most of them were no taller than five feet and had tiny hands.
Second, one of the greatest pianists of all time, Anton Rubinstein, had small hands, as well as his most famous student, Josef Hoffman.
Third, Sergei Rachmaninoff, according to the late Earl Wild (a personal friend) had a span of a fourteenth, yet he played most of his octaves in a broken fashion.
Finally, my initial post on this website spoke to the fact that pianists in the 18th, 19th, and early 20th centuries regularly rolled/arpeggiated their chords. Enclosed is my video link illustrating this.
Like I said, you, personally, do not have a problem. However, your new teacher, who barely knows how to teach someone how to pump gas, does.
Get a new teacher, and explain the information in my video, which by the way is based on voluminous historical performance practice research. Then, forge ahead and learn the great music associated with this great instrument.
Good luck to you.