CPU problem after new installation

Not so long ago, I built a new computer by putting the best I could into it. Very efficient processor, 64Gb RAM etc.
Since then, the computer worked fast, efficiently, and without any problems. The projects with Spitfire, VSO, and Kyescape, for example, did not pose any problems for the processor.
After installing C12, suddenly something started to happen. The fan (I have liquid cooling) works constantly. When enabling eg Spitfire Appassionata, I have to change the audio interface buffer to its highest value, at which, of course, due to latency, there is no recording option. By checking the performance, the CPU is working at the level of 12% or a little bit more.
HDs (all SSDs) are also not running at “high speed”. However, the audio performance meter behaves like a madman - everything on red, and the audio starts dropping.
Have any of you experienced the same? Is there a solution, maybe someone would share the method to improve efficiency?
Intel Core i9 9th Gen - Core i9-9900K Coffee Lake 8-Core, 16-Thread, 3.6 GHz (5.0 GHz Turbo) LGA 1151 (300 Series)
GIGABYTE Z390 DESIGNARE LGA 1151 (300 Series) Intel Z390 HDMI SATA 6Gb/s USB 3.1 ATX Intel Motherboard
CORSAIR Vengeance LPX 64GB (4 x 16GB) DDR4 3200 (PC4 25600) Desktop Memory Model CMK64GX4M4B3200C16
Windows 10
UAD Apollo x4

Make sure you install the latest maintenance 12.0.20

Already done that. No improvement.

A post was merged into an existing topic: Cubase 12.0.20 performance issues