If you are unable to edit a quote check the status of your quote whether it is in Draft, Submitted, Awarded etc.(Title of status may vary company to company)
ServiceBox by default has this setting where DRAFT is the only one that can be edited in the system ,If it is in anything except "Draft" status you can not edit it.
You can check under Settings -> Quotes -> Settings
All status's except Draft are likely set to 'YES' for No Recalculations.
However, you can always change these settings but best way would be to keep DRAFT status the only status for recalculations.
