https://churchonthecorner.us/questions-on-faith/how-the-bible-aligns-with-science/
Obviously the bible isn't a scientific textbook. And it wouldn't matter if you thought it was a true account or a collection of stories. A 5 second search shows the bible is filled with modern day scientific concepts. Check the link above for details. Some examples are an expanding universe, the water cycle, air currents/jet stream/weather patterns, ocean currents, & ocean floor topography to name a few.
So unless you think the bible is a modern day hoax to hide flat earth from the masses it's more than feasible and highly likely biblical authors knew the earth was a sphere. I don't have a link to the thing I came across earlier, but it suggested that in some of the passages in the Gospel of Luke alluded to Jesus knowing the earth was a sphere.