Top: VLA 6 GHz light-curve of J1023 from the June 2024 observation during the flaring period, with 1-minute time binning. The radio emission shows multiple flares of similar duration, with green and yellow regions indicating flux rise and decay phases, respectively. Second panel: The same light-curve split into two sub-bands centred on 5 and 7 GHz. Third panel: Evolution of the in-band spectral index α on 1-minute time scale. Here the radio flux density follows S_ν ∝ ν^α. Rising phases display flat-to-inverted spectra, while decay phases are generally optically thin. Bottom: Time-resolved and integrated upper limit on the linear polarisation fraction of the radio emission.