I have Quicken Classic (Premier) 9.1.0, running on my Mac with MacOS Tahoe 26.5.1. For the past few days, Quicken can't download transactions from Vanguard. Each time I try, Quicken asks me to re-input my Vanguard credentials, to no avail. This has happened before, and eventually it is resolved. I'm hoping this will solve itself in the next day or two.