Assuming you own in the NW/4 and SW/4 the lots are the reason for the difference.
Typical Section: NW/4 (160) and SW/4 (160) = 320 Acre Your lease was for 198 acres 198/320 = .61875
Since yours is a correction section it’s actually NW4 (156.44) and SW/4 (156.84) = 313.28
.61875 * 313.28 = 193.842 acres