NAV BAR doesn't render, but it works

Guys, I set up the NAV BAR in my app and it was working perfectly. Until something occurred and the NAV BAR just doesn't show up. in TEST MODE.

I've already gone through the settings and layout, but I couldn't solve it. Note that in place of the bar there is a gray rectangle, but it does not render icons or labels. And yet I can navigate through the NAV BAR by clicking on the areas of this gray rectangle.

I found that when changing the system display settings (Windows), in Scale/Layout from 100% recommended to 125% it works again. And if I run the app on my smartphone, it also works. Does anyone have any suggestions? I can't move forward anymore.