I suspect the problem relates to the early re-entry into service. Remember OQB had gone to Dresden. Now it did get I believe an engine overhaul and a big maintenance check but Iimagine it was ALSO scheduled to have the interior upgraded with a planned returned to service perhaps in March or even July.
I suspect it got pulled out of that, and having had the latest maintenance check and engine overhaul etc in DRS it was the best airframe to fly from that point of view.
I suspect OQD requires more intense maintenance - maybe a C or D check or something before it can take pax (despite ferrying in from LAX) and that is what is going on now.
Remember you don't just pull the tarp off a plane, stick the key in and off you go. Significant work required.
The irony or perhaps sad irony is that the decision to bring the 380 back earlier on was probably made before Omi took real hold, and the capacity is possibly not required now anyway (but the apparent 787 pilot staffing issue is also a factor or could be).
Seems a bit of a perfect storm. They wanted the capacity, probably did not see the IEF or seat issues happening, or considered them "minor" (I disagree) and/or fixable quickly (clearly not the case!) so customers suffer.
just my two cents