Opening Acrobat opens Reader instead, Acrobat does NOT appear in 'Open With' Menu

I have 2 versions of adobe on my machines. I have an old version of standard and the new Acrobat Reader DC that everyone downloads for free. I open 90% of my files in Reader because it's easier and I like the tabs when viewing multiple pdf's. Sometime in the last 2 weeks though something has completely changed on all my pc's. Acrobat doesn't show in my file list. When I click Open With... Acrobat is nowhere to be found. When I search for the program and select Acrobat to open a file, it instead opens with Reader. It seems the only way to open a file in Acrobat is to open acrobat and find the files. Like I said, this is a completely new situation. I've had both programs installed on several machines for years without issue. So what gives? Why does everything default to the Reader and why can't I find Acrobat in the Open With menu?