Media Management issues

I'm trying to sqeeze the size of my projects by using Media Management in davinci resolve. But it seems like in version 18.1.4 build 9 here came unpredictable problem - now when I'm trying to export my timeline half of my media comes offline and have inproper timecode. As you can see on the screenshots half of clips seems to be okay, but it's not - it's a different part of this clip, and also the 2nd half of clip is just media offline. It seems like it's a bug of a 18.1.4 build, but I can't switch back on 18.0 version because of database incompatibility.

This problem doesn't show up when I transcode my media, but this way doesn't fit me, because I have footage with alpha channel and can't effectively sqeeze the size of media and preserve alha on some clips (h265 on mediamanagement could be the solution, but it doesn't offer an alpha channel output option like on delivery page)

Blackmagic, can you fix it, please? It's a very convinient instrument and I want to use it, but now it seems to be broken(

P.S. I also tried to import timelime in new project, different database - unfortunately it doesn't work

Looking at your timeline, it appears to be composed of MP4 files. That's rough for workflow: because there's no embedded timecode, and there's a high risk of file name conflicts, that can be a trainwreck for Media Management and workflow. Long-GOP H.264/H.264 files can be a nightmare for post for that reason.

The first thing I'd do is convert all the files to something like ProRes 422 or DNxHR SQ, consider those the "new masters," make sure none of the timecodes or file names conflict. "Render in Place" might be a good way to do this, or you could just render out Individual Clips and then relink manually. Once that's done, then do Media Management. That's one of those things that ideally you'd do prior to editing the show together, because it's one of those problems that just rolls downhill the longer you don't fix it.

Well, that's not 100% correct, even if I hate to contradict Marc. While his suggestions are definitely helpful, you'll need time and space for the conversions.
Other than most other NLEs, DR can actually read TC from mp4 clips – if there is any. Check if the TC for your original clips always starts at zero or at different values.
If all are zero, the alternative would be adding TC with a tool like EditReady. And then, make sure that you have no identical names of clips. This alternative applies if your hardware is working smoothly with your mp4 clips. If not, Marc's suggestion is the better one.

The first thing I'd do is convert all the files to something like ProRes 422 or DNxHR SQ, consider those the "new masters," make sure none of the timecodes or file names conflict.

Well, it doesn't solve my problem. As I Said, i'm trying to squeze my projects, but with your suggestion the size of it will be enermous. Moreover, there are only 2 files on the timeline, they are 2 hours long each and are cutted in multicam way, but then I decomposed it before mediamanagement.

Lastly, it worked perfectly on the same files in the same projects on previous version of resolve, but now it's not. That's why I Said it's a bug of version 18.1.4, and maybe the problem exists in all 18.1 versions

and there's a high risk of file name conflicts, that can be a trainwreck for Media Management and workflow

I also want to show you, how media management succeeded in previous versions - it has cutted all the way through 1 file with 00 timecode and did the job right - all new files had connected perfectly