Advent Culture not spreading to Occupied AI planet

I've been playing as the Advent and have discovered on multiple occasions that my culture will not dominate enemy AI occupied worlds. It works fine on minor factions, but I cannot get it to work on planets that are occupied by a player. In my screenshot below, I have culture coming from two neighboring phase lanes and have used proselytize on a planet (with no broadcast center) and my culture will not begin to dominate the planet. This is a huge issue as it renders the Advent's Conversion mechanic useless.