Opening a file from Dropbox in a third party app displays files slowly, sorting incorrect

I'll try to explain the strange behavior of Dropbox. Please also note that English is not my native language. Windows 10x64 system. About three days the following happens. If I run Windows Explorer (Win+R) everything is fine in the Dropbox folders as it should be. If I click on the Dropbox icon, the folder opens and everything is fine in it too. However, if in a running application I want to open a file that is located in the Dropbox folder, I press the Open button (or Ctrl+O), a window opens and I see the files incorrectly.
They are sorted incorrectly, instead of "By date of modification" they are sorted in a strange way, it seems as if by Name (but not really). If you wait about a minute without doing anything, then they sort correctly as they should.
Therefore, I cannot open files that I have been working with recently. Because they are not on the top. If you click on the sort arrows above the columns, nothing happens. Dropbox takes a lot of time to sort files correctly. And this only happens in the "Open" window of my application.
And if you select different folders, you see that the files there are also sorted incorrectly. Although the sorting type is selected correctly, as can be seen from the arrow at the top of the column (The selected view is list).
What is most strange is that this happens on two independent computers and they are connected only by the same Dropbox account.
What was done:
various versions of dropbox were installed 191.4.4995, 194.4.6267, 196.3.6775, 195.4.4995.
Advanced reinstall has been performed. The dropbox cache has been also deleted.
The number of files in dropbox has been reduced. The remaining files were reorganized into new folders. The application was also reinstalled with a different version. Nothing helps. The file sorting is still incorrect for some reason.  And the list of files seems to be loading. Whereas in Windows Explorer the file list is visible instantly and correctly sorted.
I'm ready to reinstall the entire system, but the fact is that the same problem is on a second independent computer. And the only thing they have in common is Dropbox.
My experience in dropbox is at least 10 years. I've never seen anything like it.
All the files Available offline (online-only unchecked and never used).

Home internet direct line 200 Mbit/s, no vpn, no proxies.

My working files are small (10-100kb), there are hundreds inside the folders.

But everything was fine even when there were thousands of them.

Only 50% of dropbox storage used.
Any ideas?

Thank you!