Halion6 set up issues - noise after 3-4 mins

I’m looking to upgrade my 2001 Alesis QS8. I’m considering a Nord Stage 3 but it is very expensive. Friends advised me to try a VSTi and save my money for other uses. So, I downloaded the Halion 6 demo for 30 days. I have a new Dell XPS i7, 16G, and dual SSD. The PC task manager shows only about 20% utilization using only one instance of H6.
My problem is that after about 3-4 minutes of live playing H6 or HSE, or Prologue all start having huge noise issues! Oddly, I can play drums via GroovAgent without any issues at all. If I record the midi notes and playback via H6 the audio is clean. But, if listening to the playback and I active the monitor button the noise is instant.
I’ve tried 128, 256, 512, and 1024 buffer settings. After two days of efforts I call Yamaha tech support and they remote into my system. They are stumped and punted into “researching” this issue. During this evaluation H6 is the only resource active in Cubase and no audio is being recorded, a very light CPU and Drive load on this WinX 20H2 PC.

Is my goal to concurrently record 16 channels of audio and one instance of H6 not realistic? Perhaps I need a Stage 3 for 18 channels of audio only on my Soundcraft Ui24R. Perhaps VSTi are best used for overdubs only without many concurrent audio recordings. I was hoping to avoid the cost of a hardware solution. I’ve seen Macs used in live concerts using Omnisphere with perfect results. So, I know this is possible, which is a lesser load than my goal.
Any thoughts on this issue? Would Omnisphere be a glitch free option?

I downloaded the ezKeys demo. It took 1 minute to configure the stand alone app. It works perfectly at buffer 128. Looks like my hardware is not the issue using QS8 as the controller and old school midi.

I did not hear from Yamaha tech support who are researching this issue after they remoted into my desktop.

Still waiting on Yamaha tech support to figure out why I am getting noise after 3-4 minutes of clean audio from Halion 6 demo. I did get a great price on Omnisphere and might just uninstall H6 demo unless I get answers soon. I wasted 3 days trying to get glitch free audio. Tick-tock…