When copying larges numbers of files from MTP (e.g. an Android phone, for me this is typically hundreds of photos) some file modification times are randomly not set to their original values. As files are being copied their mtimes in the destination folder are initially set to the current time, but then adjusted afterwards to their original values. However, this adjustment does not happen for some fraction of them (maybe 5%), and the modification times of those then remain as "just now" in dolphin (or maybe e.g. "3 minutes ago" if the copy operation took a long time.)

The workaround is to sort the copied files by time, delete all those that got the wrong file date, and repeat the copyinguntil all files were copied correctly.

STEPS TO REPRODUCE
1. Plug in an Android device with hundreds of photos.
2. Navigate to its photo folder in Dolphin (mtp:/ location)
3. Open a local folder in another dolphin tab.
4. Select and copy a large number of files from the phone in the first tab. 
5. Paste them into the other tab.

OBSERVED RESULT
A fraction of the copied files get mtime = the time of the copy operation.

EXPECTED RESULT
All copied files get their original dates.

SOFTWARE/OS VERSIONS
Plasma Version: 6.4.5
Dolphin Version: 25.08.1 
KDE Frameworks Version: 6.17.0 
Qt Version: 6.9.2

ADDITIONAL INFORMATION
Has been present in several previous versions of Dolphin.