That sounds right.
I'm not too sure what could be going on as a one off - could you possibly have the patch zip instead of the full zip?
It might also be worth trying a redownload of the assets anyway in case something went wrong with the file randomly - the direct link is https://mega.nz/file/LnZWyDoD#gSMjN9SB_Qd16H05pngh8rCQE0Sm-xR6bJW9xEKMRBA