I understand what you want to do, but you are not telling my what you have in your bin in either the TAPE column or the SOURCE FILE column.
Did you start with AMA or not? When in Resolve did you only color correct or did you do any editing whatsoever? Are you conforming original camera clips or linking to the Avid MXF files for color correction? Are you correcting individual clips or a mixdown of the sequence? This information helps in defining a workflow that will work.
If there was NO editing done whatsoever in Resolve and only correction applied to the clips or events in the timeline, the easiest method is to transcode to your DNxHD resolution on the deliver page (typically with some handles applied) and back on the edit page, highlight the sequence/timeline and export AAF from there. NOT A NEW AAF, but the same AAF. This process updates all the new media links but leaves the sequence and all its effects alone. But this only works if there were no changes to anything in the timeline other than color correction. Move the transcoded media to the Avid MediaFiles/MXF structure in a number folder. No need to import mob file, just import the AAF exported and it will relink.
If you did do editorial changes, then transcode with handles, import the msmMMOB.mdb file like you did. But we are back to making sure that the proper REEL ID’s have been assigned, especially if you conformed to camera originals. Once you import the msmMMOB.mdb file, display the TAPE column and make sure that the values on each clip is what you expect them to be, and are the same as what was used on the clips in the sequence you are trying to link to. Once you can confirm this to us, we can take it to the next step.
Or if you want, Scott Freeman did a rather detailed guide to roundtrip conform. These steps may help in your situation.
https://library.creativecow.net/freeman_scott/AVID-Framerate-Metadata/1
Michael