Dan.
From the information provided it is almost impossible to suggest anything definite, you appear to be the only user out of many hundreds experiencing this issue so it is something specific to your computer.
In your opening post of the thread you state that the problem appeared after the recent updates.
Which updates are you referring to, Windows 10 or PixInsight?
For Windows 10 updates there have been reported problems across the internet that after each major Windows build is released (1903 to 1909, 1909 to 2004 etc) that disk re-indexing following the OS update sucks up CPU resources and the computer runs tasks slowly.
If there are many Gb of data stored on the system then re-indexing of the drive(s) can reduce the performance of the computer considerably for several days following an OS update. The MS recommendation is to leave the computer switched on but idle for a day or so to allow re-indexing to complete.
If you are processing large amounts of data and continually creating and deleting files then re-indexing never completes and in this scenario the recommendation is to switch search indexing off in Windows. This does mean that if you want to use search services in Windows then each search will take longer but otherwise there are benefits for computer performance if search indexing is disabled for data intensive applications.
In some cases, where many Gb of data are continually being created and deleted (which is normal for PixInsight) the Windows search index file (.edb) becomes so fragmented and bloated that it severely impacts on computer performance and in this case the .edb file should be deleted and indexing disabled, you can find instructions how to to do this via a web search for instructions.
If your computer CPU supports hyper-threading check in BIOS that hyper-threading is enabled.
For maximum performance with PixInsight where disk swap is an integral part of the processing model it is important that disk encryption is not used. Several of our students here have enabled bit-locker disk encryption by accident and then complained that their application software is running slower, check that disk encryption has not been enabled on your system.
In PixInsight check the threading settings, open the PixInsight Global Preferences window (top toolbar > Edit > Global Preferences>, click the 'Parallel Processing and Threads' tab and click the 'Load Default Page Settings' button then apply global (click the round blue dot, bottom left in the window).
While still in the Global Preferences window click the Directories and Network tab and check that your swap folders are set correctly and that Swap File Compression is not enabled.
Reboot PixInsight after making any changes in Global Preferences for those changes to become enabled.
If you have third party AV software installed, temporarily disable the AV software and test to see if that is impacting performance when running scripts.
Lastly, for Windows 10, check the integrity of the base OS by running the Windows DISM and sfc \scannow tools as described here:
Other than the above I can't think of anything else to suggest, PixInsight is running scripts normally on my Windows 10 (2004 build), macOS Catalina and Linux systems, all running the current and up-to-date versions of PixInsight.
William.