Timestamp Questions inreach mini vs. gpsmap66

On my inreach mini I'm able to see the time a message was sent or received by my device as well as the time another inreach user actually sends a message to me  (or when it reached the satellite)    The functionality is the same whether using earthmate or on the device.  

For example: they sent at 12:00pm and I received at 12:20pm,  I can see the 12:00pm time by looking at the details of the message.     

However, when i send a message to a gpsmap66 user, they would see the the 12:20pm time that they received the message in both places, also when they go into the details (where you would expect the sent time).   So for some reason it's not getting the actual sent time.  

It is pretty useful to know when a message is actually sent.   Is there a setting or workaround for this, short of manually putting the time in every message you send?  Is this a device limitation on either side?