Originally Posted by drummerboy
I guess if that isn't possible, is there a way to prevent Sigil from automatically "correcting" and closing tags? ...
Sigil is NOT CORRECTING your error (open <span> tag) by closing it for you. What it is doing is assuming the <span> was intended to continue past the end of one <p> and continue in the next all the way to the end of the document. To "fix" things so that they work properly, it closes the <span> at the end of the <p> and re-opens it in the next <p> so that it can continue properly.