After DataSource.Invalidate() new PagedList has only one page

I want to share my research in case anybody is interested:

1. Issue ("lack of feature") is known, at least I've found the couple related discussions on official tracker one two
2. If you are using PositionalDataSource or ItemKeyedDataSource you should dig into the direction of requestedStartPosition/requestedInitialKey from initial params as this answer says. I didn't have much time to build the whole solution but those params are indeed different for initial load after invalidation

About my case : PageKeyedDataSource. Here you can read that there is no similar to requestedInitialKey params in this type of data source. Still, I found a solution which fits me, very simple, although, feels like a dirty trick:

When loadInitial() is called after invalidate() in-memory cache returns all already loaded pages instead of just first one. At first I was worry that something will break if, for example, requestedLoadSize is 5 but the result is 50 items list but turns out it's just a hint and it can be ignored. Just don't forget to pass nextPageKey which corresponds to the last cached page and not the first one.

Hope it will help