I Have The Solution!
I edited a long video with drone footage, screen captures, iphone video (H2.65) and even nested sequences. It had many effects and audio & video tracks. It all worked seemlessly in premiere pro but once I exported it in 4k H2.65, The two picture in pictures and all the effects and audio worked fine but the drone footage was frozen on the first fram of each clip.
I tried everything, including all the solutions mentioned here and nothing worked. I was so frustrated because I had spent hours editing this footage. I have had things happen in the past so every so often, I save a copy of my work as it progresses just in case I make a some fatal error like this happens. I went to several of the saved premiere files and tried exporting them. They all did the same thing.
I tried making a new project file with just some drone footage. I am using a DJI Mini 3 Pro and recording 4K30 H2.65 .mp4 I can tell you confidently that it is an issue with adobe and DJI footage. I'm sure everyone on this thread with this problem has a DJI drone.
So here is finally what I did that worked:
I uninstalled Premiere Pro and reinstalled it.
Then I held the alt/control button to bring up a reset menu upon opening. I chekced all four options. You may not have to check all four but I did in my frustration and desperation. At the very least check the two that say "clear media cache files" and "reset plugin loading cache".
Once Premeiere opened back up, I also deleted the media cache files. To do this you launch premiere but don't open any files. Open Preferrences/media cache. Click the delete button next to the phrase "Remove media cache files". When the option box opens up, choose the option that says "Delete all media cache files from the system" and click OK.
Once you have dont all that, close and open Premier again. You can now open your saved project file and export it in Premier Pro. It will work! However, if you want to use Media Encoder, threre are a couple more steps you must take.
Uninstall Media Encoder. and reinstall it.
Then open it up and go to Edit/preferrences/Media/Media Cache Database and click clean. Then click OK and close Media Encoder.
Here is the important part. Don't leave Media Encoder open and just send projects there to export. Media Encoder has to be opened a new time for each project that includes DJI drone footage. If it is open from your last export, close it. Then don't open Media Encoder, click file/export/Send to Adobe Media Encoder in Premier Pro.
You can batch export in Media Encoder, just don't forget to close it after that session and re-open it through Premier Pro again next time.
I know it's a lot but At least it will work now. I hope this helps anyone else who is having this trouble.