Results of the KVN observations at 22 (blue), 43 (green), 86 (orange), and 129 GHz (red). Each panel shows the total flux density, linearly polarized flux density, polarization degree, and polarization angle (from top to bottom). The two time periods that we focus on in this work are shown in the gray shaded regions and discussed in Section 3.1. The magenta shaded area indicates a flaring period in polarized emission.