Press P in editor won't show navmesh, Enable Drawing option turned off automatically every time launch the editor

As title described, I found that in certain maps, pressing P won’t show green nav mesh anymore, so I checked settings - it turns out that “Enable Drawing” in the navigation settings has been turned off by the engine. The strange thing is, every time I re-open the editor, the enable drawing is set to off again, even previously enabled.
What could be the cause of this and how I’m I able to fix it?

Thanks in advance!

Also, every time after I fully build the map, the nav mesh will turn off “Enabled” by itself.
This is really annoying and strange…