I see a couple of reports from users saying that trackpad stopped working on 63 and 64.
Some examples from Googlers:
https://listnr.corp.google.com/report/85041313737 64.0.3282.134 beta
https://listnr.corp.google.com/report/85049696993 64.0.3282.134 beta
https://listnr.corp.google.com/report/85073243383 63.0.3239.140
https://listnr.corp.google.com/report/85058205506 63.0.3239.140