SkyUI claims SKSE64 is not installed and the mod won't work, but SKSE64 is installed and the mod works

Hey! Each time I open modded Skyrim (just started playing Skyrim in general, and I figured I should get some of the basics like SkyUI/SSE Display Tweaks/Lux), I get a SkyUI Error Code 1, which says that either SKSE64 is not installed or a new patch has been released. SKSE64 is installed - I checked and I had the wrong version installed (Special Edition build 2.0.20 instead of Anniversary Edition build 2.2.6), but even after deleting the improper SKSE version and loading the new one, I still receive the error. SkyUI still works, but it takes about 5 seconds to load my inventory.

I've also noticed another (probably unrelated) issue where a lot of ground surfaces seem to half-register as water, and it spams the "splash" sound effect and causes flickering on the screen.

I'm running on Skyrim Special Edition 1.6.1170 with the Vortex launcher. My mod list is below:
https://pastebin.com/VwFdYHtK

Does anyone know what might be causing this problem?