Full scan intermittenly completes in 5 minutes

Windows 7 Pro SP1 x64

NIS 20.2.1.22

 

About two weeks ago, my scheduled Full Scan intermittently started completing in five minutes (and 164k items scanned). The usual duration is 15 minutes (and 224k items scanned).  When it completes in five minutes, the “Statistical Submission” messages always appear:

Statistical Submission ebook.api Exonerated
Statistical Submission ccme_base_nonfips.dll Exonerated
Statistical Submission ccme_ecdrbg.dll Exonerated

 When this started, I was at NIS 20.2.0.19 but got upgraded to the current.
The Full Scan settings are the default and the Full Scan completes with no errors.

Please advise.
Thanks much.