I am using Thunderbird 102.5.0 and my email from ATT/Yahoo is showing up in TB with no problem. I didn't set TB up at first to include the calendar, but I have now added it. To do that, I followed all of the instructions here to Create New Calendar (On the Network), and in the 'Create New Calendar' dialog box where username and location were to be supplied, I put my email address as the 'username' and I put the ICS shareable link that ATT/Yahoo provided as the 'location'. The ATT/Yahoo calendar was discovered and Thunderbird now has this calendar listed in the left-most panel. I have it set to refresh every minute. Sometimes there is an 'enable' icon that appears beside the calendar name and when that appears I click on it to enable it. But the calendar itself (exported from ATT/Yahoo and imported to Thunderbird) shows no events that are in the ATT/Yahoo calendar. It's empty. So, apparently, even though Thunderbird as made the connection via the shareable link, it doesn't know how to 'read' the ICS ATT/Yahoo calendar so that the events show up in the TB calendar.

I need some advice on how to get the ATT/Yahoo calendar events to show up in the TB calendar.