May your CPU can’t keep it up with the desired graphics settings? The sim is CPU hunger and 4k, (almost) everything in ultra at KLAX wouldn’t be surprised with this result… TAA and DLSS just helps graphic card but not CPU. The overlay you use gives false result of the CPU utilization. To check the performance of the CPU use the in-game one where you’ll see much detailed information or just tune down glass cockpit refresh rate to medium and TLOD to 100 or 200 for example. You should see better results straight. Yeah, won’t be that pretty, but it is, what it is. From there you can fine tune the settings until you get the FPS you want. This may helps