Thunderbird 52.1.0 and XN 3.5.23 and... Yahoo

No Thunderbird forum; Thunderbird is a related product to Firefox, thus posting here.

Just a note that... finally I notice something wrong on one of my accounts... on Thunderbird 52.1.0 with X-Notifier 3.5.23 ...Yahoo is no longer being checked although when I click the account on the XN icon drop-down list, it goes right into my inbox.
However, it certainly looks different... owing to the fact that Thunderbird is not a full browser implementation, so it can't render the website the same as Firefox.
Perhaps that is why my Yahoo stopped being checked... maybe Yahoo's changes broke some compatibility with Thunderbird/XN. However, Firefox 53.0.2 with XN 3.5.23 is still checking all my accounts, including Yahoo (except deviantART, for which its script needs updating).

As not too many of  you run Thunderbird, I don't expect too many confirmations of this glitch.
If someone can tell me it works for them... I'll start troubleshooting ;) :(