This is normal behavior, as from March 13, 2020 residential and business Internet usage is no longer calculated.
This is part of the measures applied by Videotron to facilitate telecommuting in times of crisis: https://videotron.com/residential/p/services/covid-19/A-psku13490133e
All data caps have been removed on all Residential and Business Internet plans for our customers until April 30, 2020 (please note that this does not apply to cellular data).
Have a great day!