I'm currently doing the wet races series in F1 World, but the entire grid has to start on slicks. The AI pits on every lap going from softs to softs.
I've had another issue when starting races in other series or challenges where the engineer gets on the radio immediately after the start to report a change in weather, while it is completely dry. Nothing happens with the weather, but the AI still pit every lap going from soft to soft.
The race line assist is being messed up with this as well, as it only shows the braking point for full wets.