I can't tell you how many times I've collapsed the Navigator panel while clicking just slightly to the left or right of the "Fit Fill 1:1 1:2" words. Their click box is set so that you have to click precisely on the word itself or the Navigator panel collapses. I collapse it multiple times an edit accidentally because I'm used to buttons with larger click boxes. A proposed change would act something like this: "| Fit | Fill | 1:1 | 1:2 |" where clicking inside the bars gives you the desired perspective and never collapses the Navigator panel. You wouldn't even need to show these divisions graphically, I just used them to illustrate the proposed click box. Essentially the perspective choices would become clickable buttons instead of just highlighted words. Perhaps even a button animation showing the user they've clicked something could be implemented as well.
Another quick fix would just be to limit the collapsing of the Navigator panel to clicking the word "Navigator" or on the arrow the the left of "Navigator." This way accidental mis-clicks would produce no result but the Navigator panel would remain open. I seriously doubt anyone who collapses the Navigator panel by clicking one pixel to the right or left of the word "Fill" actually intends to collapse the Navigator Panel.
I've never experienced this issue or the one you describe at the below link.
It appears you have a problem with your pointing device (mouse, trackball, tablet). What are you using and with what OS and LR version?