When Skyrim first came out I completed it with no major issues. There were a few bugs but nothing that stopped me playing.

I recently reinstalled because I've never played the DLC's but i'm having an odd graphical issue. When I walk for a period of time in the open world the plant and grass will eventually stop loading leaving the environment a bland washed out texture. There is not a single plant. Along with this if there is supposed to be any buildings such as watch towers and small houses they will not appear. I first noticed this problem after leaving the first village at the start of the game to goto Whiterun. At the spot where the mecenaries are usually fighting the giant there was instead empty ground. No giant, no farm, just blurry textures.

The weird thing is when I press escape, which pauses the game, this causes all missing assets to suddenly be loaded in. The process is instant as if it was just waiting for a pause. The problem also has an effect on AI. If a hostile NPC is in an area where i'm having the issue their combat AI will not go off. Pressing escape will load the missing assets and also allow the NPC to attack as normal.

Just to be clear my PC is more than able to run Skyrim and I have completed it once back when it was first released and on the same computer. I am not using the HD textures but do have all the DLCs installed. Graphics drivers are up todate and the card is a Nvidia gfx 590 for reference. I have the FPS limited to 60 fps to avoid the physics bugs.

Has anyone else ever had these issues? I couldn't find anything like it by searching.

edit: forgot to say I have the game and DLC via steam