Default sizes aren't respected on nested allotments when visible is false by default

[vonangelo]

On later versions (>= v1.18) there seems to be an issue when using a combination of nested allotments, default sizes and with some pane invisible by default.

In my scenario, I have a outer allotment with two panes - both visible all the time and with sizes set. In the right pane, I have a inner allotment with another two panes - left is visible all the time and the right is invisible by default, but can be shown by a button click, also with sizes set.

If using v1.17, everything works just fine. But using versions above mentioned, the invisible pane is shown with a much smaller size when set as visible. Hopefully it makes sense.

Here's a codesandbox fork showing the issue: https://codesandbox.io/p/sandbox/nested-forked-36vhnq
As mentioned before, if I simply change the version to v1.17, everything works just fine.

Am I mistaken, or is there a different newer way of achieving this result? I can't seems to find it anywhere.