Is this a common problem on 777s (e.g. do they use a different toilet type than other aircraft?)

I had a VA flight from AUH-SYD that was delayed by a full day because someone dropped a toothpaste tube down the lav and created a waterfall that flooded the aisles.

Iirc, there have been a few other cases of overflowing sewage on long flights on 777s - unfortunately the articles don't tend to mention the aircraft type, but they involve avid operators of the type (9W, BA, CO). But it's possible it's just sampling bias because diversions are more notable for the kinds of long segments the 777 tends to fly...