[Gambas-user] sidepanel object + gb.gtk bug

[M0E Lnx]

I develop a couple of application in gambas2-2.9.0, both of which have
a sidepanel object. Both use gb.gtk.
I've found something that I believe is a bug. Does not happen when I
use the gb.qt component

When I click the little "<" on the side panel (to hide it) it goes
well, but when I click it again to restore it, it will not restore it.
The little arrow will only turn the other way, but the panel is still hidden.

I can drag it and resize it back to normal size, and hiding/restoring
after that works flawlessly... but the first time it gets stuck.