Inconsistent letter spacing in random paragraphs when compiling to epub on Mac

Hi, I have used Scrivener for years, but compiling to epub is new to me due to the change with Amazon. After compiling to epub, I am getting inconsistent letter spacing throughout the book. That is, most of it is spaced one way, but a number of paragraphs are showing up more tightly spaced. I have gone through and verified that it is all in the same font style and size (Helvetica). The problem shows up both with regular and italics. When I look at the original formatting within Scrivener it all looks the same. I have re-compiled, closed the program and compiled again, but nothing seems to change. My beta-readers are telling me this interferes with reading comfortably. I will attach some screenshots as examples.

Had something similar happen to me once because the “random” paragraphs were not marked with the same Scrivener style or label.