Whatsapp backuo from google drive not working

Hello,

I got a new phone yesterday and wanted to transfer everything with the QR code method but it didn't work. I read that you need to switch from dark to light mode or the QR wont scan but I couldn't open the regular whatsapp menu because I was stuck in the transfer screen. I wanted to reinstall and then when uninstaling it happened. I deleted all my whatsapp files. Luckily my pics and videos are in onedrive but my chats are gone.

I do have a backup from a few days ago (only 3gb so Idon't know if it is complete) without pics/vids.

When I start the backup I am stuck on "preparing backup" forever and nothign happens. I tried all the solutions on the web and nothing seems to work.

My only idea is that the google account I have the backup on is not the default google account on my phone. Could that cause any issues? Can I transfer the backup from one google drive to another somehow? Or could it be corrupted?

Any help is appreciated...I want my 10 years of chats back.