I did do a search on Calendar and I see that there are a lot of instances for problems with the Calendar for Windows and Macs.
I run Quicken Classic Version 7.10.0. I have had this same problem for years
I suspect that I have a lot of transactions/accounts in my file for the calendars view.
Symptom:
No Calendar entries are shown with all three selected (transactions, balances and investment changes) for all accounts
I have seen that If I select one of the above and wait 30 mins, I might see the current month but that is rare.
Trouble shooting:
I created a Calendar with only one lightly used checking account and I select balance and transactions, it did displayed the one entry each (correct) after a waiting a few minutes.
I then added another highly used checking account , it takes about 5 minutes to populate all of the entries for the month. If I scroll a month, it will show that month. If I scroll back, the calendar is blank for all months. If you wait another 5 minutes, the process starts again.