I can't use che checkbox on Firefox browser...
I tried to deactivate all the plugins, but it still doesn't work
Open Developer Console (Ctrl+Shift+K) on the Time page and enter the following command:
['','label','input','span'].map(s => s + $$('.timer-td-checkbox ' + s).offsetWidth)
Send a result to us.
Also, check if the problem exists in a new clean Firefox profile. To create it, run Firefox with parameter:
Please give us any other details that can be helpful to reproduce and fix the issue.