Issue: After over a year of normal gameplay on this machine, Minecraft suddenly lags for about a second at a time, approx. every minute or so.
 
Clues: 

• Task manager shows Minecraft constantly running between 90-100% CPU while GPU stays at 0%
• The NVIDIA GeForce Experience App shows Minecraft as the only game with "Game isn't optimized" label and reverts back to this message every time I try to optimize it 
• Other 3D games still utilize the GPU and do not lag/hog the CPU

Recent Changes: 

• I manually updated Minecraft through the Microsoft store on 3/19 in order to play on my friend's world (it said "Outdated client" when I tried to connect) but I cannot find a change log to see exactly what changed. The issue appeared immediately after.

Things I have tried:

• Reinstalling my NVIDIA driver
• Verifying that Minecraft is present and active under the NVIDIA GeForce Control Panel "3D Settings"
• Turning on Hardware-accelerated GPU scheduling under Windows Settings and setting Minecraft to High Performance (this did begin to use the GPU at about 8% utilization but my CPU was still running at 100% and lagging the game so I changed it back)
• Confirming that the Primary Graphics Adapter was set to "PCI Express" rather than "Onboard" in my BIOS configuration

Things I have not tried:

• Reinstalling Minecraft (not sure how to back up my data)

 
Please see the attached screenshot for an example of this issue in action. A second screenshot featuring a different 3D game (Outer Wilds) and how my CPU and GPU handle it compared to Minecraft is also included. This appears to be isolated to Minecraft and perhaps may be the direct result of the most recent update through the Microsoft Store.