My landscape moves way up into the sky when i open landscape editor....

My level consists of a persistent level and one sublevel.
When I go to landscape editor mode, the whole landscape from the persistent level
travels far up along the zed axis and loses all heightmap data. I am completely unable to edit my landscapes (both persistent and sublevel) because this issue that suddenly occurred. I have other separate levels within my project that are not experiencing this issue…any advice?