having the same problem. CCleaner pro trial updated 2 drivers and then it just closed. I thought it maybe wanted me to restart so I did, then after the restart CCleaner Pro Trial will not allow me to update any more drivers. When I click "update" it just tells me to buy Pro. It still says I have 14 days of pro trial left and all other features seem to be functional.
CCleaner says I'm on version 5.82.8950
using windows 10 home Version 20H2