I see this a lot among newer players- they're asked to switch their loadouts, they do so, but they don't realize that they need to hit customization complete. This can result in the start of a match being delayed by up to a few minutes while the captain has to help that crew member out.
To fix this, I think that a popup should appear when exiting the character/ship screen indicating that the changes won't be saved, and that they need to hit customization complete. Then there'd be an option to never display the popup again, and bam. Problem solved.