Lost WhatsApp images after switching to new iPhone

I switched to iPhone 14 last week. I backed up WhatsApp to iCloud from my old iPhone before switching. I have all my chats and videos restored, but images are missing. When I go to media, I see very few thumbnails and for the rest, I see a '?'. How do I recover my images? I have read about version mismatch being an issue, but the iOS and WhatsApp version on my old and new phone are the same. I had some very important images and I want them back. I still have access to my old iPhone. Please help! TIA.