Is this Oldrim or SSE? Looks like SSE
You say no mods but you had a texture pack - what texture pack?
Is there anything else you've had installed? SKSE, racemenu, an ENB, reshade, anything at all?
What exactly did you do to install and uninstall the texture pack?
And what did you do to clean install the game?
Step by step. It's possible a bad file from the mod is still there.
And also as a bonus - have you tried different anti aliasing settings?