Not too familiar with Liverpool ops/based carriers, but I know Easyjet do have a base there.
Could it be that they have had problems because their a/c have been parked over night and thus would require de-icing in the morning, whilst the other 2 who (and I'm just assuming

) don't have a base there and may not require a de-ice on such short turn rounds, having been done or not even needed at their home base - therefore are able to continue their ops whilst Easy cannot ??.