OK... I figured out what's going on... I think...
It appears laji is using the file directly from the Calibre folders. As PeterT mentioned that filename is normalized and used STRICTLY BY CALIBRE.
The reasons for this normalization are spelled out
here and
here. This will not be changed, and I agree with those reasons (if that matters...lol).
One solution for laji is to simply use the Save To Disk function. This will automatically save the file with whatever filename/order you want - in UTF-8 - in whatever location you want. After that, if it doesn't show up in Acrobat properly, then that is an Acrobat problem.
You need to set your Save To Disk options in properties with the appropriate information. From laji's first post I would recommend: "{author_sort}: {title}" See image below:
Cheers,