Hello
the same thing happens to me with Thunderbird 52.9.1 (32 bits) on windows 10 64bit, Lightning 5.4.9.1 and Provider for google agenda 4.4.1.
I have created 2 more calendars on my google account (the first one has been successfully used for years in thunderbird) but cannot see them when trying to add them in TB.
I activated debugging and this is what I get :
[calGoogleSessionManager] Reusing session *******@gmail.com gdataSession.jsm:71:13
(the asterisks added by myself in place of my email). Thanks for any help!