"The html5 formatter is much less aggressive about escaping ampersands, in a way that generates cleaner HTML but could break your project's test suite if you compare Beautiful Soup's output to pregenerated HTML snapshots.....
[and]
a larger-than-usual number of deprecations and changes that may break backwards compatibility.....
This version drops support for Python 3.6."
three of the changes in the new Beautiful Soup beta (per https://wandering.shop/@leonardr/113783579673634848 ) - please test!
And now @leonardr has "released the biggest update to Beautiful Soup in many years." Upgrade to 4.13.1 to enjoy better warnings, type hints, generated API docs, and more.