Importing LOS prices from channel manager

Hi!
I have a website with a CMS. I upload my rates from there to booking.com and everything works fine besides the LOS table. I receive the following error: "403 LOS Pricing Forbidden, use the Default Pricing instead".

Does someone know why? Am I supposed to enable something or booking.com does not support LOS pricing sync at all? If so, is it safe to build a LOS table on booking.com while syncing with my website ?

Thanks a lot!