I support two family users of Thunderbird 115.2 who have both installed access to my Google calendar. After providing access to that Google calendar on both PCs, the calendar is shown formatted by Thunderbird, that is without colors etc as formatted when accessing the calendar as a webpage via Mozzilla. A) On my machine, if I close my calendar page within Thunderbird, and option to access my google calendar appears at top line of T'bird screen. That leads me to a calendar page formatted similar to a webpage view of that calendar. I can. for example, insert and see color detail on a calendar entry. B) On the other PC - my wife's - that option does not appear and access to the Google calendar is shown with only Thunderbird formats - none of the color detail added on other interfaces such as my PC via T'bird calendar function, or simply web page access via Mozilla. I'm puzzled about the difference between those installation - A and B. How can I get "B" to function like A ? I suspect there may be a residue of earlier changes to synchronise T'bird and the Google calendar.