[Sheree Scott]

Hi there.
It could be either. I reckon that at 19 mo it could be big wees as they can often start to hold on by this age. One hour doesn't seem very long, but a big wee is a big wee whenever it comes. My heavy wetter outwees or maximum fills any nappy I can throw at her bottom when she actually wees. For example, not that long ago when out all morning she managed to have leaks from a pretty heavy duty nappy - the morning she hadn't wee'd before we went out. I now add a microfibre if I expect an extra big one. It seems a shame the wee comes when you are out!!!!
That aside, while I have had a few months of erratic big wees, needing extra boosting etc, my DD has now moved to weeing more regularly and wanting to use the potty and pants, so perhaps it is a sign of a move to summer toilet training (although she's a bit young, but if she has the skills that is not a problem!!).

If you don't think she is holding on, then perhaps you do need to look at a strip wash (I've never done one, but there are lots of threads on it). Lazy me would probably look at doing a hot wash with an extra final rinse as a starting point and see if that helps.

HOpe you find a solution soon. I suppose the test would be that if the leaks don't resolve when you add extra boosting to the nappy (if a fitted even add it to the outside if the inside is a bit bulky), then you have a repel issue. If it is the liner that is repelling, it might be quicker to replace the liner.
Just a few ideas, hope you find a good solution,
cheers,