I've faced this issue twice: after selecting my seats well in advance, I was assigned to less desirable seats as soon as online check-in opened. The airline seems to disregard seat selections unless you're a premium customer. On my second trip with family, we were scattered in different seats. They claimed the flight was full and couldn't accommodate changes, despite several exit-row seats being available. Those seats ended up occupied by staff instead. So much for their claimed 'operational reasons.' Now, if I have to fly with this airline, I won't bother selecting seats—they'll just relocate you wherever they want.
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