I need to use SU with a pending deadline days away so after a gap of about 2 weeks using SU with no issues back then, I tried to use it again today .. only to find slow select tool has resurfaced again in my case!!
I am desperate and I need to work with SU now ... today ... tomorrow ... and the rest of this week!!
I can confirm success as Chixy advises above (3 days ago).. by uninstalling Windows Update KB4019472, SU is back to normal (fast/instant) select tool. So I am grateful for that advice. Thank you Chixy.
I don't want to have Windows defeat me again in hours/minutes/days ahead, with an automatic update download, so I decided to take responsibility for the timing of my updates using the following advice, and turning Windows updates OFF, until I decide to turn them back on using "Services" control.
Control Panel->Adminstrative Tools->Services->Windows Update control panel
The following article explains my procedure the consequences and obligation I now have.
I cannot let Microsoft control my life as this recent SU saga has shown. Totally unacceptable!!