Spell Echo + Spectre (Slave Drivers) doesn't work

I've a 4 link :
Raise Spectre - Minion Damage - Elemental Focus - Spell Echo.
My spectres are Slave Drivers (found in Act 5 first zone after town).

The problem is that the Lightning Surge skill that they use does not trigger twice like it should with Spell Echo. It tried removing Spell Echo to notice any difference (and every other gems either) and in fact that doesn't seems to make any difference when I had Spell Echo in my link, they only cast their skill once and also the cast speed is very slooow (spell echo cast speed doesn't seem to work either). Considering that those spectre usually have a high cast rate even without Spell Echo, I instantly noticed the problem.

There wasn't any problem with those before 3.13 patch.

Other spectres/skills might be also bugged with Spell Echo, I haven't tested those yet.

Could it be due to the changes to Syndiacte Operatives skills that would affect all spectres for some reasons ?

Edit: For some reason, after getting Spell Echo to level 4, my Slave Drivers started to double cast their Lightning Surge skill. But, if I get a lvl 3 or lower Spell Echo, they don't cast twice..

Noticing this myself. Good to hear that it fixes at spell echo 4, but this is still really annoying.

So my Spell Echo is 15 now and it still isn't working :/