RUE
Can you provide a sample file?
Sure, I have sent you a google drive link which has 2 folders (original & proxies), you can import the original file to Davinci Resolve and try to link those proxies and sources together.
Note that, when you are on the metadata tab, you will see TC start & TC end have a little bit different (+- 1 frame) when compared to the original files (also in the link below)