SSlv3

I’m having problems suddenly with our Simple Checkout though Authorize.net. When someone fills out the registration form (Ninja forms plug-in) they are then redirected to a confirmation page with a simple check out button from Authorize.net. Authorize creates the code for you and you just copy and past it into your page and voila done. There’s no plugin for this. We are having the problem that when people get to this page sometime the button will work taking you to the payment page and sometimes it will not. It acts as if it’s not linked. After speaking with tech support from authorize.net he suggested it was outdated browsers and we ruled that out. I then asked if WordPress could be blocking the connection. He said possibly if it’s using SSlv3 which Authorize is no longer supports. How do I know if I’m using SSlv3? How do I make this work? and can that even be the problem if I’m not using any plug in. It’s really just a linked button that takes you off site, all the code comes from Authorize and none from WP so how is it even possible that WP is blocking it?