Good evening Mike and welcome back!
Thank you for reaching out to us.
I would love to help you with this topic.
Most likely, what is going on is that your current import settings are limiting the range of the import from Google Calendar (I am guessing the current value is 1 month).
You can tweak those under Events -> Settings -> Import.
If you have not already done so, please read the following: https://theeventscalendar.com/knowledgebase/event-aggregator-import-settings/
Let me know how that goes.
Best regards,
Geoff B.