Spacers caused massive death wobble?

Hi everyone, I fitted some alloy hubsentric direnza 30mm wheel spacers yesterday to our 54k 06 jimny. I am still waiting on the second pair to arrive in the post as I bought them of eBay and thought it was 80 pounds for four, turns out it was only two...
Obviously I'm quite annoyed I had to pay 160 for these already, well basically I fitted new discs and pads yesterday and thought why not throw on the front spacers.
It drove lovely on my test drive but then when the missus was driving home later exiting the motorway it threw a massive scary death wobble, I took it out and sure enough at 45 it had a few less severe shakes, I went to the local garage and set all the tyre pressures (one rear was at 11psi, have to keep an eye on that)
It wasnt as bad but still quite apparent.

I came home and removed them, could it be because I only fitted the fronts.?
Is it worth fitting all four at all?
It drives perfectly again now, doesn't feel nearly as nice as with the spacers on tho...

I just looked at the spacers and they arnt hubsentric even tho I'm sure it said they was in the listing....
I'm thinking maybe my fitment was to blame. Possibly I should have taken more care trying to centralise the spacers and the wheesl on the spacers and gradually torque all the studs down together....
I read a topic on a Jeep forum where someones wrangler was doing it and refitting as above sorted it.

Dunno if putting spacers on should cause problems like that. I reckon putting spaces on may make death wobble more obvious but not cause it like that. Plus don't think putting on spacers is a job that needs loads of care, they should surely just sit in the right place. If I was being tidy I'd maybe clear out sludge from under them if I was doing something that required taking them off.

But I reckon moral of the story here might be don't trust ebay! bits4vits and jimnybits sell em and you can trust them, not checked but probably get them on the bigjimny shop too.

I thought the nuts would centre them so I just whacked em on, who knows.
Does anyone think having them just on the front and not the rear could have been the problem?

Did you torque them up using the star method? As far as I can tell your alloy bulldog spacers are the same as the jimnybits raptor ones and just branded differently.

I have fitted -30 offset wheels before and it gave me death wobble. They were a lot heavier than the alloys.

Try them on the rear the steering won't be affected.

I think you need to check the listing if there not hub centric like they said they are then send them back and get your money back, jack the front up and check for any play/wobble