Using Mac OS X 12.6.8 and Remote Desktop 10.9.2. Beginning two versions back (10.9.0?), copy and paste works for a while after launching RD, but it eventually fails when copying from the remote mach...
I'm experiencing this issue as well, it's very frustrating. I've posted a ticket in the Azure Remote Desktop section for this; feel free to upvote so hopefully this gets more traction.