EMP after aplying several times not work or fireworks prevent it use?

Hello
We fight against Harvester and first my teammate spam small EMP and after several use it seems start affect lower and lower. Same time I start to use fireworks cos there was a small robots around. And we cant understand why EMP affect lower - because of many usage on same robot or cos I spam fireworks and them replace EMP effect?

And EMP affect for every robot same or every robot have different resistance to EMP?

The Apoc harvester appears to have a resistance to small EMPs, sometimes other Apoc machines can resist them a bit but not often. Youre better off using the Medium, Large and Car batteries instead.

So there is different resistance at different robots?

Well we fight with common and military harvester and tank. And it seems after spaming small EMP after some time they have imunne to it…

Cant say ive noticed any resistance to EMPs from Prototype and Military. Every time its succeeded, then again i normally EMP once and get weapons off and leave it there. Might be worth trying that instead, there is a chance there is some resistance after time