​@nathan10 This is a known bug. There is a similar thread here that you may want to look at regarding a similar issue.

​@Micah might be able to help you further.

Thanks for the reply. But I don’t think this is the same issue as I’ve had my Lucidchart for almost two years and nothing has changed in terms of master pages, etc. it’s seems like a bug that just appeared. 

Hi ​@nathan10, thanks for this post, and apologies for the trouble! In that third screenshot, those thick dashed lines indicate separate pages at the page size you’ve set, and if you have auto-tiling turned on (File > Settings > Document settings > Canvas and page), moving objects over the boundary of a page will automatically create a new page. I wonder if perhaps there is an accidental object somewhere on this particular tab that is causing this extra whitespace to appear, since you’ve verified that the master page is applying normally. Would you please try using Ctrl/Cmd+A to select all objects on that tab and identify if there are any outside of the intended area that might be causing this?

Thanks Micah! Tech support gave the same solution which did the trick with auto-tilting. I’m the only one who edits this document so not sure how that feature got turned on to only some pages. My only guess was a software update caused this but not sure.

​@nathan10 I’m glad to hear that this resolved the behavior for you! That does sound unusual and not intended, though, so please don’t hesitate to come back to this thread should you see this crop up again. We’ll be ready and eager to jump back in!