Possible IE Mode bug - window.open with pdf target causes Edge to adjust zoom

Here is a log showing the zoom changing without user interaction. The redacted URLs are both the same, but it seems like Edge is correctly reading the 100% zoom preference, then pulling 80% out of nowhere.

System used has 3 displays. 2 at 1440p w/ 100% scaling and 1 1080p at 125% scaling. The zoom changes on the 1080p display. I believe it is possible to duplicate on any display scaling other than 100%. 

[17692:17376:0831/153523.492:VERBOSE1:dual_engine_tab_helper_win.cc(250)] CheckInternetExplorerNavigationEntry URL matches IE11 or NEUTRAL rule on sitelist: [REDACTED]
[17692:17376:0831/153523.492:VERBOSE1:internet_explorer_tab_host_win.cc(661)] SetZoom zoom_percent = 100
[17692:17376:0831/153523.493:VERBOSE1:internet_explorer_tab_host_win.cc(1076)] OnDocumentModeSet document_mode = 110000
[17692:17376:0831/153523.493:VERBOSE1:internet_explorer_tab_host_win.cc(1261)] OnHasBeforeUnloadChanged has_before_unload = 0
[17692:17376:0831/153523.513:VERBOSE1:internet_explorer_focus_watcher_win.cc(39)] IE focused:0000000000111006 IE window:00000000006B165E
[17692:17376:0831/153523.523:VERBOSE1:internet_explorer_tab_host_win.cc(483)] OnLoadingActivityChanged is_loading = 1
[17692:17376:0831/153523.523:VERBOSE1:internet_explorer_tab_host_win.cc(453)] OnFinishedSetFocus old focusing_ie_timer_ running = 1 browser_window = 00000000006B165E focus = 0000000000111006
[17692:17376:0831/153523.541:VERBOSE1:internet_explorer_tab_host_win.cc(511)] RequestHostWindowFocus is_focused = 1
[928:4832:0831/153523.617:VERBOSE1:network_delegate.cc(32)] NetworkDelegate::NotifyBeforeURLRequest: https://business.bing.com/api/v3/bookmarks
[928:4832:0831/153523.824:VERBOSE1:network_delegate.cc(32)] NetworkDelegate::NotifyBeforeURLRequest: https://graph.microsoft.com/v1.0/me/people?$top=1500&$select=id,displayName,jobTitle&$filter=personType/class%20eq%20%27Person%27%20and%20personType/subclass%20eq%20%27OrganizationUser%27
[17692:17376:0831/153524.493:VERBOSE1:internet_explorer_tab_host_win.cc(1261)] OnHasBeforeUnloadChanged has_before_unload = 1
[17692:17376:0831/153524.499:VERBOSE1:internet_explorer_tab_host_win.cc(1063)] OnZoomChanged zoom_percent = 100
[17692:17376:0831/153524.553:VERBOSE1:internet_explorer_tab_host_win.cc(383)] InternetExplorerDidNavigate pending_nav_entry_id_ = 0
[17692:17376:0831/153524.557:VERBOSE1:dual_engine_tab_helper_win.cc(250)] CheckInternetExplorerNavigationEntry URL matches IE11 or NEUTRAL rule on sitelist: [REDACTED]
[17692:17376:0831/153524.558:VERBOSE1:internet_explorer_tab_host_win.cc(661)] SetZoom zoom_percent = 80
[17692:17376:0831/153524.571:VERBOSE1:internet_explorer_tab_host_win.cc(1076)] OnDocumentModeSet document_mode = 0