Hi, I want to advise everyone how to remove of "TCP segment of reassembled PDU" packets in Wireshark for OpenWrt

There's likely nothing "wrong" (or "evil") about that message. It's just wireshark collecting packets together that it believes are related into a "complete" protocol unit. Unless you've set the MTU lower on an interface than you "should" (or you have an application running that is unexpectedly sending jumbo packets over a "conventional" link), it's most likely just TCP working as expected.

See, for example, https://osqa-ask.wireshark.org/questions/58186/tcp-segment-of-a-reassembled-pdu