You may have done this already, but I would suggest searching for 'chrome' in the BP forum here and read all the posts in the last 2 weeks or so where others have been having issues with spying Chrome.
The various issues are usually caused by the Chrome 72 update. Chrome 71 spying in browser mode works in Blue Prism, but Chrome 72 does not. I heard that the 73 beta update works, but I have not confirmed that myself. However, I have tested/confirmed myself that Chrome 71 spying in 6.4 works whereas Chrome 72 simply doesn't work at all with browser mode.
Dave Morris, 3Ci at Southern Company