Optimise import uses prettier settings in one project but not another one!

I have two projects. Both have identical .prettierrc and .editorconfig in the root of the project.

In one project when I organise imports, spaces are stripped from the import lines and I have to reformat to put them back (reformat code is configured to use prettier in both projects).

In the other project when I organise imports, spaces are retained correctly.

I can't spot any obvious difference in the settings for the two projects.

It's more of an annoyance - I have format on save set, so generally spaces will be added back before commit, etc. But sometimes the "bad" formatting creeps in!

Any pointers how to track down the discrepancy? Thanks