If you go into your server admin tools then go into Services>System you should have these 2 services:
PublishingTools
PublishingToolsEx
I ran into a similar problem when I upgraded my SDE DB to SQL 17, and I was using ArcGIS Server 10.5, I had to upgrade my Server to 10.6, because 10.5 was not compatible with 17, but one of major problems was I did not have the PublishToolsEx service.
Chad