Lightroom cannot open DNG file exported by itself.

I am having problems with DNG files exported by Lightroom from Canon RAW-burst sequences. If I extract CR3 files from Canon RAW-burst sequences, I can open them with Lightroom (regular Lr, LrC, and also Ps) without any problems. They are just like regular CR3 files. But if I export them as DNG from Lightroom after some edits, then I cannot open them again with Lightroom (or Photoshop).  This bug makes the workflow for Canon RAW burst files really tedious because I need to be able to transfer my

edits from Lr to LrC.

Is there a solution? (Apart from saving my edits as xmp).

(I tried to attach example CR3 and DNG files to this post but they are rejected. It says "The attachment's example_csi_9416.dng content type (image/DNG) does not match its file extension and has been removed." )

Thanks.