WhatsApp videocall answer with no video

Hi, I noticed recently that when I receive WhatsApp video calls with phone locked, when I answer the call it is audio only, if I press the camera button then the caller starts seeing me and I start seeing him. Previously I could answer the video call directly without having to activate the video.

This has been happening to me for several weeks, I don't know if it is a WhatsApp update or if it is for an iOS update.

Thanks