WhatsApp giving error message "unable to back up" (Google Drive)

My WhatsApp has been giving me trouble for a long time regarding backups. It started a couple of months ago when I pressed back up now and I received an error message saying "unable to back up". A little while later, my WhatsApp suddenly crashed and when I tried opening it, I received an additional error message saying > Something went wrong with your chat history, don't worry you can restore your chat history from backup. If you don't restore now you won't be able to restore later. > After pressing "backup now", it responds with "unable to retrieve old backup from Google drive." I tried looking up different solutions and I did everything including, resetting the cache, disconnecting and reconnecting my Google account, turning off my phone, and playing around with every possible setting. I have plenty of storage on my device and Google Drive account and a great internet connection, so I had no idea where the problem was. The only solution that helped was when I switched my WhatsApp number to a different number. After that, I was able to back up to Google Drive normally as it should be. Unfortunately, I had to reset my WhatsApp from new and start again which was really irritating, on the bright side I was able to do backups moving forward. My WhatsApp has been working fine ever since yesterday when it gave me the same "unable to back up" error message I'm all too familiar with. Not surprisingly, the next day my WhatsApp crashed and the situation that happened a couple of months ago repeated itself. Please help me understand what's wrong with my WhatsApp and if there are any solutions or fixes I can do. I've scoured the internet and I haven't found any solutions that have worked. The problem now being when I press backup now I get an error message "unable to backup " in response. Any idea of what could be wrong/if some file is corrupt how to fix it?