You may be having a different issue, but I wanted to throw this suggestion out because it worried me when I first started de-winterizing.
I don't know how much time you are allowing to get the hot water side to run properly, but something similar happened to me. Since you emptied the hot water tank for winterizing, there is air in the tank and lines until you completely purge all of the air from the tank, so cold starts fine, but hot spurts air and water until the tank is completely full.
'17 Ford F-150 Ecoboost, max tow package
'13 GMC Yukon Denali 6.2L V8
'04 GMC Yukon SLT 5.3L V8