OneDrive Q regarding file access from 2 systems

Scenario: Within the root of one drive I have a directory named RESOURCE_FILES. Within that I have a txt file named MyFile.txt . 

SCENARIO1:

I am at my laptop (named MyLP01) connected to one drive and using a text editor app (note NotePad) I open MyFile.txt that is in OneDrive. If I move to my workstation (MyPC01) and open MyFile.txt using a text editor (not NotePad) I can have teh file open on both systems. If a change is made to MyFile.txt on either PC, the other will get a notice that the file has changed and tge text editor app asks me if I want to reload the updated file.  This is expected behavior. 

SCENARIO2:

I am at my laptop (named MyLP01) connected to one drive and using a text editor app (note NotePad) I open MyFile.txt that is in OneDrive. Without closing the file or altering it, I activate teh VPN to my office and then I launch RDP (Remote Desktop) and connect my pc at work (MyWORKPC01). I then launch a text editor app (not NotePad)  and open MyFile.txt located in OneDrive. When I try to open teh file after about 15-20 seconds I get an error msg that there is a problem accessing teh file. 

Why in scenario 1 can I have 1 file in OneDrive open from 2 different systems but I can't in scenario#2?

Thanks