This is a weird bug that I just found. I'm using a Mac and have 3 monitors. The OS and all Adobe products are up to date. I am not using InDesign Beta. I have two separate InDesign files open and the second one is detached from the primary InDesign panel and on the other monitor. I have the primary document selected and go to File > Adobe PDF Presets > Press Quality and somehow InDesign will export out the other document that is not selected and on the other screen. I have recreated this twice with the same result. This only happens when I have another document open and detached onto the other monitor. The pdf will have the name of the file that it should be. However, its content will be the other file. Hope that makes sense.