I am using a slightly big modpack with few mods that change enemies specifically and bullets so this might totally be the fault of that BUT, should the defensive drones instantly start attacking the hacking device causing it to die before it can hack unless you have robots to constantly repair it?

Also how exactly do you automate these things cause you can slow down the decay of the hack but you can't stop it meaning that you always have to come back, shoot it once just for it to hack for a while and then go back to being inactive (turrets aren't gonna work cause they get instantly targetted by the defensive drones)

I think most of the issues are comming from aai vehicles as always as that mod removes turrets targetting biter bases

I am using a slightly big modpack with few mods that change enemies specifically and bullets so this might totally be the fault of that BUT, should the defensive drones instantly start attacking the hacking device causing it to die before it can hack unless you have robots to constantly repair it?

The intention was for them to attack the hacking device if otherwise not threatened, but you should be able to distract them from doing it.
How does your defense look like and on which alert levels you get problems?
You definitely need at least two turrets, one that shoots the access keys, and one that attacks the bots. And how it currently works I would also expect the turrets to need repair at least sometimes on medium alert levels. Rarely at low levels.
For me the turrets were usually targeted before the hacking device, would be interesting if that is different with your setup. Could be other mods if so, or different turret placement etc. Not sure how the AI determines their targets.

For low levels, the initial bots have very long warmup time and should die before they are able to attack at all. Even with one turret with normal magazines in them.
Higher levels should be harder, but not sure yet if the current approach is the correct one. Always happy to get more feedback on this.

Alert level of 0.02 and uh just a bunch of gun turrets which just don't target them.
I am 90% sure it's aai vehicles mod fault as it tries making it's vehicles the defacto way of destroying nests but in process of that it removes stuff like turrets targeting STRUCTURES which would mean that the little robots are considered structures instead of entities which makes no sense but I would have to experiment a tiny bit more to understand the nuance of this issue.

(So my end result is just 20 aai vehicles tanks with guns but it wastes a lot of ammo shooting at the wrong stuff as you can't filter them)
It's either that or the fact that they are flying somehow messing up with realistic flying bullets. I'd have to test with laser turrets but again, can't structures would make the most sense though I have no clue how a flying unit can be a structure!

The bots are based off of biters, so not structures. I removed collision on them though so they can fly though, I could imagine that being a problem with "realistic bullets" if the way they work is checking against some collision layer.

Then yeah that is absolutely the issue and it's this mod for future reference. https://mods.factorio.com/mod/distant-misfires

I tested distant misfires and the bots did not take damage (fixed now in 0.6.4), but you said the turrets did not target them? If that's still the case there is still some other mod messing with this.

Well my only guess is aai vehicles, that popular mod that adds ai vehicles. It's a bit weird but it adds a lot of these "Things" to make you use the vehicles to destroy nests instead of turret creep which sounds great but often breaks stuff.

And at least for the hacking thing that is a problem cause turrets with aai vehicles can't target structures (that's why I'm using a tank for that but that can't be forced to shoot only one thing)

https://mods.factorio.com/mod/aai-programmable-vehicles?from=search