Dave, if you use A/C in your sleeping quarters, do this: walk over to the A/C unit, carefully pull off the front, or slide out the FILTER, and check it.
Chances are, it hasn't been looked at for several years, and is full of crud, viruses included. Wash it down twice with a green scrubby and dishsoap, and then do a Clorox scrubdown, followed by a thorough rinse, and air dry.
Inside the A.C. unit, where you can get to things, wipe down with a sponge dipped in Clorox to get rid of all the crud you can reach.
This process should stop your morning coughs at breakfast. I would suspect an A.C. unit as the cause of a chronic cough first, in the DR.