Nothing dramatic about the pods themselves....but the electricals components of the overall propulsion system have misbehaved recently.
This would NOT necessitate an emergency drydock ( unless the ripple effect of these malfunctions affect pods components.....,which would only happen if X does not attend to the current problems timely and correctly).
When failures happen in the electrical control panels, it usually limits the available power until the repairs are completed, which would restrict the ship's top speed to perhaps 75% or 80% of the normal maximum. On the Millennium class, the normal maximum is about 25 knots so the reduced maximum probably would be around eighteen to twenty knots -- certainly enough to force shortening or even cancellation of scheduled ports of call. It realy is not possible to do anything that would cause further damage to the propulsion system because circuit breakers limit the load on a generator and the power supplied to each pod to safe levels.
The reality is that the crew can repair the electrical panels underway if they have replacemet parts onboard. Unfortunately, the ship does not have room for spares of parts that are not prone to failure and those parts sometimes have to come from the factory -- and, worse, sometimes have to be built to order. In this case, it sounds like it was not possible to get the part to the ship before the ship arrived in Vancouver. Once the part arrived onboard, it may have taken a day or two to install it and to retest the system before resuming normal operations. Please correct me if I'm wrong, but my impression is that the problem basically affected only one turn-around and two cruises.