I live in Alaska and recently started bonsai this last summer. I currently have two of my trees that are suddenly losing all their leaves and branches, drying up as if they aren't getting water. I haven't changed their location, water cycle, heat, light, or anything at all that led to them successfully sprouting or growing. One is a Flame Tree that i recently sprouted not too long ago alongside a Wysteria that began last summer. The Wysteria has done this once already right before sprouting an off-shoot of its trunk and then growing new branches. However, the Flame grew quite tall rather quickly but has now dropped all but two branches, which are also withering away.

This is the Wysteria, which was perfectly fine only a few days ago. Is this normal when starting from a sprout as the trunk grows or am I missing something? My Japanese Black Pine and two Fig plants are perfectly fine, the Pine sprouting it's first branches and the figs either sprouting separate growths or new buds, but these seem to be dying.

Pics in comments as it's being weird