One of our long-standing policies at Pro Epic is to host web forms separately from our websites. The main reason is to reduce the attack surface of our customer's sites. Many websites are hacked using exploits or weaknesses in their online forms. We eliminate that risk by hosting our forms on a different domain or sub-domain. That makes it impossible for an attacker to gain access to our customer's website by hacking the contact form, as an example.
That system has worked flawlessly for us for years, until last week anyway. Last week we were alerted by one of our customers that a page on their webpage was jumping and flashing and was unusable. When we investigated, we could not reproduce the problem. We were only able to reproduce the issue after upgrading our iPad to iPadOS version 13.3.1.