The setup:
Account A has a calendar (Cal) shared to everyone on the domain with full rights of "Make Changed and Manage Sharing"
Account B creates an event (Event) on Cal, Event is an all-day event. Attendees may or may not include Account B.
Account B cannot see Event created in the calendar on the web.
Account C can see Event created in the calendar on the web.
Account B and C have the exact same rights to Cal (they have the same Access Permissions and the same Share with specific people settings).
If Account C sends Account B a link to the event, Account B CAN open the link and view the event.
If Account C views Event - the date of Event is "Jun 25, 2019 to Jun 25, 2019." And "All Day" is checked.
If Account B views Event - the date of Event is "Jun 25, 2019 to Jun 24, 2019." And "All Day" is checked.
(Event is viewed via copy and paste of Event URL, both Account B and Account C are pointed to the exact same URL.) 
If, however, Account B views Cal on an App or in Outlook with events synced, Account B CAN see Event.
For Account B - I have cleared cache, wiped all chrome data, used a different browser, used a different computer, spun up a fresh VM with clean install. I have deleted Cal, cleared cache et al then added Cal back. I have blocked Account B on Cal - tried to access, then unblocked Account B.
I have checked time-zones. I have checked the computer's date.
I have even used the Google Calendar API to create an even with Account B, set start.date = date(yyyy-MM-dd) and end.date = start.date, but when Account B views Event that Account B created (via URL), the end date is the start date less one day, but when that same Event
Dim te As New [Event] With {.Summary = "Event Title", .Description = "Event Body"}
Dim taskDate As New EventDateTime With {.[Date] = CDate(task.Item("duedate")).ToString("yyyy-MM-dd")}
te.Start = taskDate
te.End = te.Start
Any ideas? Because I have no ideas left.
Update: If Account B opens the event in the iOS or Android Calendar app then clicks "save" without changing the event in any other way, the event will appear on the Google Calendar in a browser.
