So I'm doing a smuggling mission from robigo and despite the multiple attempts I avoid most of the NPCs chasing me. I'm 4 jumps away from my goal and I get interdected by a magic invisible NPC. But what's this? I'm winning the intetdection? Until I'm not. I go from full blue bars to all red in 3 seconds. I fail it. I'm whatever I'll just boost away. Instant thruster malfunction. Shields are gone thrusters are gone. I'm most definitely toast. I'm at 35 hull and my shields and thrusters are back so I boost away hopefully I'll get out of this yet. Nope because this NPC has unlimited rockets.
It's not that big of a deal I had rebuy money but this is very frustrating. Mostly the unlimited rockets.
Some mission related NPC's very often spawn right behind you.
This is extremely annoying as you lose a lot of escape options because of it.
I never try to escape interdiction once the tether is established.
The reason for this being that I do not get the feeling the interdiction mechanics are clear enough.
Just like you I sometimes was sure I had won the interdiction fight but then suddenly lost anyway.
I suspect that you need to win within a limited amount of time, but I am not sure.
Losing the interdiction means your FSD will take a long time to cool down, which increases the risk.
So currently I think it is best to submit and boost. Your cool down time will be much shorter because of it.
I think FD should perhaps take the time to produce a tutorial vid about the interdiction process, explaining in detail how it works and what influences it.
Nobody seems to really know, although there is a lot of speculation.
Some think there might be bugs, but there might also be factors at play that where never explained.