Hi There,
Niether I can replicate the issue, I was able to edit and saved an element on your page.
Please do the following, open your site in incognito/private mode of your browser where there is no caching and browser add-ons involve.
Then try to edit your page and see if the crashing happens, if not then you’ll know the issue is something on your browser, either caching or one of your browser’s add-on.
Clear your browser’s cache first and see if that resolves the issue.
If not, please do a test. Deactivating all your browser’s addons, and seeing if the problem remains. If it’s fixed, you’ll know an addon caused the problem, and you can narrow down which one by reactivating them one at a time.
Let us know how it goes,
Cheers!