This problem comes up and goes away, periodically.
When I export (copy and paste) maps/shapes out of ArcMap 10.8.1 I get a bunch of extra space around the map in MS Word etc. I think this may be an 'extent' problem of sorts, but I can't find a way to fix it. Images attached.
I've tried to replicate your error but didn't have any problem.
Can you share you mxd and layer?
I know it's a bit more work, but the ideal way to export a map is through the Export Map command in the mxd's File menu. There you should be able to select 'clip to map extent'. Another option is the Snipping App found on most Windows OS.
Thanks for the reply.
Yea, it doesn't happen all the time, but usually hangs around for a few weeks and then goes back to normal. Last time it took a month, and it drove me crazy! I try to avoid exporting maps because you end up with the ESRI URL reference sentence at the bottom of the map. I avoid snipping because the quality is low, especially when you resize the map.
Attached is a sample mxd and a map layer. I made a new map with just the one layer, still having the same issue, so the bug is in there somewhere!