Can someone tell me why if I have the same website in Firefix and Safari Firefox logs in ?

No one here can tell why since no one here has access to your computer. You best to take it to a computer to shop to see what is going on.

I am using a IPAD not a computer

Hi

Just to clarify, you are trying to view a website in both Firefox and Safari, but you can only view the site in Firefox?

I am using a IPAD not a computer

Firefox uses webkit as a backend since Apple has restrictions on what browser engines can be used on iOS/iPadOS. This is also why there are no Firefox extensions for Firefox on iOS/iPadOS.