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

vs official:

At the same time, the difference in the current rate for the ETH/USDT pair is obvious, which adds further confusion.