I solved that particular problem. I had to disable Kaspersky, reset the account in Quicken for online services, then re-enable Kaspersky.
But in answer to your questions, this occurred after upgrading to 2024 Kaspersky Plus.
As for browser, that is a perplexing issue. When I am accessing certain accounts, Kaspersky changes the browser, without telling me what browser it is using (and sometimes causing frustrating delays). I have one account I cannot access at all with Kaspersky operating, because it cannot be accessed through Kaspersky's "safe browser." Is there a way to turn off the browser switching without disabling Kaspersky?