Robots have always been a sticky point to me because it's yet another of those points in OTU that simply doesn't make any sense once you scratch any deeper than a nail's depth.
We know that in the OTU there's the Shudusham Accords that forbid the use of robots in war. We also know from a number of canon sources that the Zhodani Consulate doesn't follow the Shudusham Accords and used warbots extensively. It would appear that unlike the Imperial Rules of War, the 3I actually follows the Shudusham Accords itself. That the Shudusham Accords were designed to make the 3I a "human universe" was clear and I agree with it. It's just that GDW ruined it when they pointed out that everyone else didn't follow the rules...
To me, it seems, even being a TL below the 3I, the Zhodani should have been able to make major gains with the use of robotic fighters against the 3I, not just warbots on the ground, but robot-controlled ships (for instance "Berserker"-style robot battle-riders - ships without jump drive, you just drop them into a system then jump out and let these behemoths wreak havoc until they're destroyed) - the losses the Zhodani take simply don't make sense to me. Zhodani love their sons and daughters too. If the 3I got close, why wouldn't the Zhodani have just sent waves of drones at the 3I until the 3I withdrew, then sign a peace accord? That the Zhodani used warbots on the ground extensively (again, a canon point as opposed to my earlier speculation), it shows that warbots are cheap enough to be considered as a method to preserve life.
The only thing I could imagine is that the 3I perhaps has some device that can trump robots - perhaps some Ancient relic or a technology.
IMTU, I postulate the invention of a device called a DCD and a DCS. A DCD is short for Digital Cognizance Detector. DCS is short for Digital Cognizance Suppressor. Research and discovery of the principles only occurs in the 3I around late TL14 and early TL15, however, if the principles were explained (or a genius with insight came along) DCDs could be developed as early as TL13, while a DCS could be developed as early as TL11 - similar to fusion bombs and fusion reactors, it's much easier to develop a weapon that will supress digital devices than it is use the principles to do subtle things like detect it. It's the deepest, darkest secret of the 3I and are controlled directly by the Emperor. Even Archdukes aren't aware of the existence of DCD/DCS technology - when the devices arrived, Norris simply knew of them as "Specials" but never had any control over them. They were operated by special Navy units. Obviously the Zhodani and higher Imperial nobles are aware that the Emperor has some sort of special technology, but don't know how it operates or who does it. Zhodani military thinking to keep the 3I off-balance pretty much has a timetable that depends entirely upon achieving their goals before whatever this Imperial technology is arrives from its secret mustering points to the frontline.
I've never really considered on what principles the DCD/DCS work on, only that a TL15 DCD would be pretty coarse - it would have to be a pretty "smart" robot for the DCD to detect it from orbit (a TL18 one could detect a 21st century digital wristwatch from orbit). It's basically handwavium on the level of grav plates for me, just to make the Traveller world more "livable" for me. Likewise, a DCS is a large field-projector that is finicky and power-hungry and would require a specialized vessel the size of a battleship to mount to give it any kind of decent range. Under the influence of a DCS, digital devices simply stop thinking - the device itself suffers no long-term problems (unless, say, it's mounted in a jet which then crashes), it simply stops working for the duration that it's in the device's field. The effect is nearly impossible to shield against, though its effect on "dumber" devices drops to being nearly negligible - it really only suppresses "smart" digital devices. The limitations are that a DCS is large (as described earlier) while a DCD is even larger - the sensor array basically impossible to deploy anywhere but in space, requiring multiple data collection sites with a baseline around 100km for an orbital array with any useful resolution on individual warbots on the ground.
Now, many of you will wonder why the heck I came up with such an overcomplicated solution to the robotics problem. But see, I run a Traveller: TNE variant campaign and the DCD/DCS eventually will become a critical weapon against the Virus, which seems to have all the advantages against "meat" beings. The DCD/DCS is what is going to put the AIs on a more level footing with everyone else, instead of being the "elves" of Traveller with nothing but advantages.
