I’m not sure whether this bug is in Trading View charts or Zerodha because I faced same issue in Fyers too which also uses Trading View charts.
Many times the trend lines disappear while switching from higher to lower time frame.
The lines require few seconds to load and adjust in lower time frames. So, I do the following trick and its working. Keep zooming in and out the chart with mouse wheel for 5 to 7 seconds on the time frame at which trend lines are visible. After that switch to your desired time frame and those lines will be visible.