Garry's Mod Depth Buffer Issue

I'm trying to get the RTGI shader working on Garry's Mod, but the depth buffer is being weird. It shows the depth, but it's glitchy. I have to enable "Copy depth buffer before clear operations" and I have to select CLEAR 2 or 4 to make it work. But there's a problem. On clear 2, the depth buffer goes underneath the world's geometry when looking towards the center of Construct, plus up and down are swapped. 

Weird, right? But there's more. When I select clear 4, when looking at the brick bunker to the left of the map, the depth buffer rendering freezes! Not the game, but the depth buffer!!!
https://lh3.googleusercontent.com/gOReCAHwrencWgg33SIBPbkU5yxoLH75MKcWaQWQwg9fkqeq51xWXIyul0vgkdIN9sARuvD1e39dJK729cRjbgOVui-GXTYi1uHjNABIWnA14y_ske5GoH2KCF_PCV2Z_o-ty7SML5bwdqgjDVK7L1F3W0mrgkzFgluW3lhBUTGbYWg-xCjDUOPhMjREAMslBQOg4xQj2FMUTRrbqKpiRvgR210nwBC6eaB_kurxZ7VPbibKtRtdTLelGMZwRVo-9fiePe9TSvTcrICVDbXu1LmmlhtTQQAu1KXGnbXOcV8RrVQ3ErYD0rclgthQiZsi_EL-SlrmqCt73kOz7QwoFjYFLhjbLSUuJ3HnY6QOUwzWSI-dcShjpPMDEeymPcfA7OkTeSQ3anGuiPRXUqd1p9XrKUat0zYJHv5WOOBFSKbzUVYQE9lZjWAAHlPr_9mZr7B01iSX2GXFb3prO4hEOsbKwfAICQQ-OTcf20Pds35AZlRbd70H3qs3SVzFfC9Ongdls4u9zQ6IX3E68AQdA45RRtRnaqCdgIt_IP2yUOK18q6O2XrvGRqgL2PETJsTs4PhLfCoLunLMaj2oY8nsYDQjynVIpkyuBNRDXRjI0wMyLnFZvQGR-Wx3Xrlk0YOrS4BET2NGIZpQkaSs6xUfHxEKomJVlvpDy3zOfel32J3zm0ns0NO8gfO9FrvkEVueiXnkIz-HupE-1crVXrpP6M=w1608-h904-no?authuser=0It freezes right around here. No clear selected, and clear 1 also work, but it only shows the 3d skybox!

Does anyone know how to fix this? Also RTGI's shadows don't work either.

I'm running Garry's Mod on 64-bit Windows 10, with the x86-64 branch enabled on Steam and Directx12 (I selected Directx9 when installing Reshade as that's what Source uses.)

Have you found a solution?

Hey i had the same issue and i found a solution!
Go on steam > setttings > cloud and disable clolud synchronization. Then go to program files 64x > steam > userdata > 1032123349 > 4000 and delete all the files inside. uninstall and reinstall gmod and have fun!