In England we often use this phrase as a pleasant surprise that you were not expecting! For example. “in a weird way it was much better than I thought it would be.” Good luck with your English learning!

It depends on the context. It can be used to describe unusual or odd behaviour - something that makes you feel uncomfortable. "Somebody on the bus smiled at me today, but in a weird way, it made me feel uncomfortable" It can also be used to talk about how something has an unexpected and strange/odd effect on something else. "Even though I can no longer walk, in a weird way I am more active than I ever have been in my life"

It means '' Do in a different way which is not normal "