Oh. for some users, if it didnt work in first attempt, then they successfully transferred it in second time. Can you confirm whether any pending Whatsapp update is there with your Android phone? Because it is important to update the whatsapp to latest version as we download the latest version of whatsapp in iPhone too.
Both crypt algorithms match to make the transfer process seamless and prevent any data loss.
You can see the backup file by selecting “Restore WhatsApp messages to iOS Device” (https://youtu.be/orngY6ny7Dk?t=330) option. Let me know if that helped.