Unexplainable outcome of State Estimation -- Please Help

[bhanta]

I noticed something unexplainable in the state estimation.. The problem is that although a switch is in an open position, making Line 3 energised at Bus 6 end but open at Bus 7, state estimation predicts a large line loading percentage (although Power Flow is predicting zero power flow - correctly). The network utilised is:

import pandapower as pp
import pandas
import plotly.graph_objs as go

try:
#net = pp.networks.example_simple()
net = pp.from_excel(filename="C:\Bhaskar\pandapower_work\res_pp.xlsx", convert=True)
net.measurement.at[2, 'value'] = 6.5
net.measurement.at[19, 'value'] = 1.2
net.measurement.at[20, 'value'] = 0.5
net.measurement.at[16, 'value'] = 1.7
net.measurement.at[17, 'value'] = 1.0
net.switch.at[5, 'closed'] = True
net.switch.at[4, 'closed'] = False
pp.to_excel(net=net, filename="C:\Bhaskar\pandapower_work\res_pp.xlsx", include_empty_tables=True)
net = pp.from_excel(filename="C:\Bhaskar\pandapower_work\res_pp.xlsx", convert=True)
success = pp.estimation.estimate(net, check_existing=True, init="flat")
pp.to_excel(net=net, filename="C:\Bhaskar\pandapower_work\res_pp_est.xlsx", include_empty_tables=False)
joined_bus_est = pandas.DataFrame.join(net.bus,net.res_bus_est, how="outer")
joined_bus_pp = pandas.DataFrame.join(net.bus, net.res_bus_est, how="outer")
joined_line_est = pandas.DataFrame.join(net.line, net.res_line_est, how="outer")
joined_line_pp = pandas.DataFrame.join(net.line, net.res_line, how="outer")
#print(joined_bus)
except Exception as e:
print(e)
exit(1)

fig = go.Figure()
fig.update_layout(title_text="Bus Power")
fig.add_trace(go.Scatter(x=joined_bus_est["name"], y=joined_bus_est["p_mw"], name="Estimated Bus Real Power"))
fig.add_trace(go.Scatter(x=joined_bus_est["name"], y=joined_bus_est["q_mvar"], name="Estimated Bus Apparent Power"))
fig.show()

fig = go.Figure()
fig.update_layout(title_text="Line Loading Percentage")
fig.add_trace(go.Scatter(x=joined_line_est["name"], y=joined_line_est["loading_percent"], name="Estimated Line Loading%"))
fig.add_trace(go.Scatter(x=joined_line_pp["name"], y=joined_line_pp["loading_percent"], name="PP Line Loading%"))
fig.show()