"The Javelin can defeat Arena while in top-attack mode, due to the missile descending from too steep an angle for the system to engage properly."
https://mwi.usma.edu/on-killing-tanks/
It can defeat Arena-E that way from any aspect, but the non export version (which did get some upgrades) not so much. In order to successfully top-down-attack the upgraded (but still older) Arena, it has to attack from the ‘blind’ 60 degrees in the back of the turret. Javelins were fired against Russian tanks in Syria to little effect, most being shot down by Arena.
You may also want to look at the replies to the article below, especially Jakub Janovsky’s reply. There are many factual errors and assumptions in the article and he sums many of them up nicely.