Like fonzy explained
but not only bugging the ed% from the jewel, also bugging any existing ed already in the item
which is why the 2 cases I talked about were funny fails
There's people who spent big bucks on some perf/near perf Ars Dul Meph and protector jewel for their echo lock
They expected to gain big dmg
But instead, they removed the 115 ed% already in there, which is huge as it multiplies very high base dmg from echo, also multiplied by 10 as you got 5 echoes going out, 5 going in.
So they got some really low bonus min/max dmg, but lost multiple Ks of dmg.
And I mean... even the guide on maxroll made by one of our favorite noobs is making this mistake, misguiding so many people.
Look at that XD
https://maxroll.gg/d2/guides/echoing-strike-warlock-guide