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Yes, that's true. It is possible to add all PST like date file to my Outlook and fully work with them, regardless of its location and/or type od connecting. All I/O operations with them are possible except for connecting from EZOS.
Okay, then my only guess would be the specific Outlook version that you have. Will try to get it to check if that's true.
Now I have Outlook pro Office 365 MSO ver. 1910 (build 16.0.12130.20334) 64bit (it has changed by Windows Update since last). Windows and Office are in Czech language and Office with "Click and Run" technology.
Any new idea, please?
No, not so far, unfortunately. As we're still unable to reproduce the issue on our side even with the precise Outlook version your mentioned.