28GB of space left on a 32GB SD card; still can't move apps. ERROR: "not enough space"

I have an LG Stylo, marshmallow 6.0. It's an 8GB device with 2GB of internal storage left on the device. I also have a 32GB sd card with 10 apps installed on it. I currently have 2 apps on the internal storage that can be moved to the external storage. For some odd reason, my phone will not let me move the apps, and a message pops up saying, "not enough space." WHAT?? There's 28GB of space on the card! Why isn't it letting me move these apps? I have 2GB of space on the internal storage; however, I bought the card so I could install apps to it. 2GB is going to fill up pretty quickly. I would love to know how to fix this issue. If anyone out there has an answer (I've searched the internet high and low with no luck on how to fix), I would really appreciate your help!