although your transaction is lean(small) using only 190 real hard drive bytes.
the wishy washy code of segwits scale factor falsely makes it appear that your only paying 4byts/sat. thus not as much of a priority as other transactions that would have paid more

paying $0.28 cents and not getting in after 3 hours is not the 'promise' of 2015 which said segwits wishy washy code meant to sort out.