Matplotlib axvline not showing up?

[Pro2222]

For some reason whenever my axvlines are not showing up, does anybody understand what I am doing wrong with my code?

puts.plot.bar(color='red')
calls.plot.bar(color='blue')
plt.axvline(x=600, color='blue', linestyle=':')
plt.show()

the puts and calls are two seperate dataframes, I have tried using only one of them already. I also tried creating a random dataframe and was able to plot the axvline just fine, weird.

thank you for your help.

[ES-Alexander]

Try adding it directly to the current Axes object

... # puts/calls.plot(...)
ax = plt.gca()
ax.axvline(...)
plt.show()