As Ben hinted at, make sure you start X-Plane with --num_workers=11. Also, look at the frame profiler, it'll help point at a particular part of the frame rendering that's being slow.
You’re not on Linux so please don’t use a totally unrelated thread for your issue, it’s confusing for everyone.
Step 1. Disable Zink, it’s not supported by CL-650 1.7, and was auto-enabled by LR in 12.1B1.