Jupyter Lab interface icons are missing - how to fix?

I have encountered a problem in Jupyter Lab: the icons in the panel menu and the panel bar are not listed. Instead, I see empty spaces where their icons should be (screenshots attached).

Here is what I have already tried to solve the problem:

• Cleared the browser cache.

• Reinstalled Jupyter Lab.

• Updated Jupyter Lab and depending on the latest versions.

• Made sure the browser was updated to the latest version.

• The new old version of Jupyter Lab is launched from Anaconda Navigator, and the new one is launched from the terminal. However, there are no icons in both.

Unfortunately, none of these steps helped

I found it! It's because of dynamic visualization.

First, I restarted the kernel with clearing all outputs. And the interface icons appeared! So it's a cell issue.

I started running all the cells one by one and found the problematic one. It didn't change the settings in any way. It was just that the visualization output on it was kind of bad and I didn't like it right away. But I didn't immediately notice the interface failure and didn't connect it with the output problem.

Now, instead of outputting to the screen, I set saving the results to a file and the interface miraculously recovered! And the output in html itself looks better.

Here is the code that breaks:

pyLDAvis.enable_notebook()
lda_vis = gensimvis.prepare(lda_model, corpus, dictionary, sort_topics=False)
pyLDAvis.display(lda_vis)

Here is the code that creates:

lda_vis = gensimvis.prepare(lda_model, corpus, dictionary, sort_topics=False)
# Saving visualization to HTML file
pyLDAvis.save_html(lda_vis, 'lda_vis.html')
print('Visualization saved to lda_vis.html')