Problem with Bookings - calendars are gone from my profile, yet they're still active online

[loganmacd]

I am a teacher - I created multiple booking calendars for classes I teach, for the purpose of setting up meetings with students.  When I last logged into Bookings, I tried to "Open" one of my calendars (to make some changes in the backend about my availability), however I was met with the message "We can't find any booking calendars". All of my booking calendars are gone. Nothing, but the calendar I most recently made is accessible in Bookings. 

However, oddly, my calendars still remain active online.

So the problem is that I now don't have backend access to make changes to the calendar, I can't even delete them if I wanted too, but yet they remain live for students.  Basically, I can no longer update the bookings pages I created. Any ideas on how to fix this?

Here is the error message I receive:

Even as I just open the search bar (without actually typing anything to search for), I get the "We can't find any booking calendars" message... 

Yet, here is an active link to the calendar, which I created: 

https://outlook.office365.com/owa/calendar/FINEINDG216@uofwaterloo.onmicrosoft.com/bookings/

[#2]

I have the same issue. I am fairly new to Bookings and just have two setup but now cannot go back to configure the first. Like you, the inaccessible calendar is still active.

[#3]

Same finding here: As an administrator I recently setup multiple bookings but cannot show/switch between them anymore.
Don't know if this is related, but since we don't wanted booking email addresses in our Global Address Book (GAL) , I did hide them by PowerShell 

$mbox = Get-Mailbox  -RecipientTypeDetails Scheduling  | Where-Object -Property HiddenFromAddressListsEnabled -EQ $False
foreach ($box in $mbox) {
	Set-Mailbox -Identity $box.Id -HiddenFromAddressListsEnabled $True
}

 Don't know if this is related? However even after I unhide them, issue remains.
@loganmacd  @andrewrowatt  Were you working with hiding from GAL, too?

[#4]

In my case, the issue was caused by our internal IT department "hiding" the Bookings entries in the Global address book. They have undone that action and now the Bookings are accessible. Sorry that I don't know the specific details.

[#5]

@andrewrowatt Thanks a lot for your response, since this confirmed my worries: Hiding (some) booking calendars from Global Address Book crashes the functionality. So I could fix it also on my end, by undoing the Hide with

$mbox = Get-Mailbox  -RecipientTypeDetails Scheduling  
foreach ($box in $mbox) {
	Set-Mailbox -Identity $box.Id -HiddenFromAddressListsEnabled $False
}

[#6]

@loganmacd I was creating a How-to for a conference and went through the motions of creating a new calendar.  Now my original calendar is not showing in the carrot, nor can I find it as you stated.  I'm reaching out to MSFT to see what else can be done.