Hey everyone,
Do you also have WooCommerce installed with Yoast on these installs?
In 5.10.1, we had to work around a bug in WooCommerce where they’re loading a non-select2 compatible version of SelectWoo by mistake, but calling it select2. They’ve got a patch already merged to core for their 5.7 release – but until then, I think it’s possible that Yoast + WooCommerce leaves us a case where this could happen.