Only for a specific page: update leads to "The connection was reset"

Dear community,

I have trouble only with one specific page (not post) of my site when I try to update it. I updated several other pages during the same session and didn’t encounter any problem.

Description of the problem:

If I make changes to this specific page through the Editor and hit the “Update” button, I immediately get an error message with “The connection was reset” (in Firefox). When I hit the back button, the update hasn’t been made and the history hasn’t been updated.

It is possible though to change the page title through the Quick editor. Changes will be saved and the history will be updated.

I changed the content of the page through the database and the change is displayed correctly in the Editor when I reload the page in the Editor. The problem remains nonetheless.

The only thing that makes this page different from others is that it has a parent page. Also if I try to change this (hence no parent page) in the Quick Editor, the Save icon will turn for several minutes without saving the change.

Any idea where the problem comes from and how I can fix it?

Thanks in advance for your help!