IFrame Integrations broken

The iFrame on our website is getting blocked even though our site does not use any cookies.

The site that is loading the iFrame is uniswap.info.

Within that site it pulls in an iframe from uniswap.exchange.

We have verified that the uniswap.exchange site does not use any cookies. However, the iFrame fails to load in any sites unless a user goes in and turns off cross-site cookies.

To test this, go to https://uniswap.info/token/0x89d24a6b4ccb1b6faa2625fe562bdd9a23260359 and click the the “buy” button. You will see the iframe get blocked. If you then switch the shield off or turn off the cross-site cookies the iframe will work.

I’m posting this topic because this seems like incorrect behavior. Why is this iframe getting blocked even though its not injecting any cookies. Is there some flag we need to use in the iframe to prevent this?

Thanks in advance.