If you’re using plt.title it relies on what it think is the “current axis” is. This would be the most recently created axis but certain operations and functions will change this.
However, if you are working with multiple figures and axes I’d highly suggest keeping a reference to each figure and axis, that way you can directly modify only the axis you want and there’s no need for you or for anyone reading your code to keep track of a hidden “current axis”, the target for any modifications is explicit instead of implicit.
For a quick example-
fig_a, axes_a = plt.subplots(1, 2)
axes_a[0].set_title("The first axis")
axes_a[1].set_title("The second...")
You can modify several settings at once if you like, e.g. ax[1].set(xlim=(0, 8), xticks=np.arange(1, 8), ylim=(0, 8), yticks=np.arange(1, 8)).