How to backup and restore MMS messages from old phone to new phone?

I switched from a Google Pixel 8 Pro to an Oppo Find X9 Ultra. At the time of the switch I utilized the built in phones copying service to bring over all my apps and messages. However, I noticed a few weeks later that not all of my MMS messages were there. I read online that it could take a while to populate them but they never did.

I downloaded SMS Backup & Restore, backed up the Pixel to OneDrive and Google Drive both. Then I downloaded SMS Backup & Restore on my Oppo phone and logged into the same account. I restored from the OneDrive backup. Once again all my MMS pictures were not in my messages. I waited for them to populate again but they didn't. I tried restoring from Google Drive and got the same results.

Are there any other apps like SMS Backup & Restore that I can try? I still have the Pixel and all the messages still on it. Or is there a manual workaround where I can move the backup from OneDrive on my computer, drop it into the phone and extract the files? I'd love to get all these messages recovered so I can finally sell the Pixel.