Photoshop CS6 turned into a "Tryout" trial version

Hi there!

I've owned the CS6 versions of Photoshop/InDesign/Illustrator since 2012, back when they came on a disc in a box. My sister bought it for me, and not from any shady third party seller. 

I changed my CC plan from All Apps to just Photography recently because I couldn't afford it anymore, as I figured I could use my old CS6 programs. But now whenever I try to launch the CS6 version of Photoshop (and any other CS6 program), a message pops up saying "Your trial will expire in x number of days." This never happened when I was on the All Apps tier. Has anyone dealt with this before? I do need to use these programs for work, so I'm a little worried that Adobe won't let me use the CS6 programs once this "trial" period expires. But I own the programs! I'm confused haha. 

I'm on High Sierra, and the "Tryout" versions of the programs work perfectly fine, so I don't think it's an OS issue. 

Thanks in advance for any and all advice!