i believe these inconsistencies are usually due to the aggregator OrangeFren data refresh speed and the fast-moving nature of crypto prices
I've seen such inconsistencies too often to blame it on data refresh speed.
Whenever I use a site to compare rates at instant exchangers, I'm looking for the one that gives me (say) 0.2% better rates. If there's a 1% variation between what's shown and what I get, it's kinda pointless.
It's not just Orangefren, I remember seeing something similar on Bestchange and exchanges listed on there.
To test one of the exchanges, for example, Swapuz. I downloaded their affiliate widget and added it to one of my sites. Here is how the conversion of 0.1 ETH to USDT (trx) looks on my site and their official site
...
Big thanks to everyone who reported the rate differences!
We've had a closer look over the weekend and decided to impose a 1% correction on fees we get from Swapuz.
Currently we check for new rates as soon as we fetch the previous batch.
Bare in mind we also interpolate, we can't query every amount, after all. It also wouldn't be a good design for user privacy to send a request for a quote every time a user searches for a pair, because if any of the exchanges we list had their query history compromised it would make it possible to timing-attack our users. Even if they didn't use that particular service.