It's currently not possible to reorder Objectives. The order in the Roadmap is in alphabetical order by the Owner, in terms of Group name. Groups that start with A appear first. For instance, the order will be Customer Service, Finance, Marketing, Sales, etc.
Also important to note is that OKRs by Group appear in the Roadmap from left to right from newest to oldest created. And Objectives per timeframe are ordered alphabetically by default.
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