A method of video coding using coding modes including IntraBC mode (Intra-block copy mode) and inter prediction mode is disclosed. In one embodiment, when adaptive motion vector resolution is selected to allow adaptive use of integer resolution or fractional-pel resolution, a resolution indicator having a value corresponding to using integer resolution for all motion vectors and all block vectors is signaled in the current. In another embodiment, if a coded block is coded in the inter prediction mode or the IntraBC mode, the coded MV or BV is converted to a converted MV or BV having fractional-pel resolution if a resolution indicator for the coded block specifies integer resolution. The system then stores the converted MV or BV for encoding or decoding of subsequent blocks.